POROUS NANOPARTICLE-COMPOSITE-BASED CATALYSTS

FIELD OF THE INVENTION

The present invention relates to the field of catalysts, and more specifically to nanoparticle catalysts.

BACKGROUND OF THE INVENTION

In solid-state catalysts, efficiency of the catalyst is based, in part, on the amount of catalyst surface area exposed to a target substrate. Smaller and porous particles can generate greater surface area for the amount of catalytic material used.

However, commercially available solid-state catalysts have been unable to fully optimize catalyst surface area.

Commercially available catalytic converters use platinum group metal (PGM) catalysts deposited on substrates by wet-chemistry methods, such as precipitation of platinum ions and/or palladium ions from solution onto a substrate. These PGM catalysts are a considerable portion of the cost of catalytic converters. Accordingly, any reduction in the amount of PGM catalysts used to produce a catalytic converter is desirable. Commercially available catalytic converters also display a phenomenon known as "aging," in which they become less effective over time due, in part, to an agglomeration of the PGM catalyst, resulting in a decreased surface area.

Accordingly, reduction of the aging effect is also desirable, in order to prolong the efficacy of the catalytic converter for controlling emissions.

SUMMARY OF THE INVENTION

Described herein are catalytic materials, including micron-sized catalytic materials, washcoat compositions containing micron-sized catalytic materials, and coated substrates formed using the washcoat compositions. The catalytic materials including composite nanoparticles, which include a catalytic nanoparticle and a support nanoparticle, along with non-catalytic spacer nanoparticles. The composite nanoparticles and the spacer nanoparticles are bridged together by a porous carrier material . By including the spacer nanoparticles in the catalytic material, the composite nanoparticles are spaced in the catalytic material to limit agglomeration of catalytic metal in the catalytic nanoparticle during extended use at elevated temperatures.

In some embodiments, a porous catalytic material comprises a plurality of composite nanoparticles comprising a support nanoparticle and a catalytic nanoparticle; a plurality of non-catalytic spacer nanoparticles; and a porous carrier that bridges together the plurality of composite nanoparticles and the plurality of spacer nanoparticles. In some embodiments, the catalytic material is a micron-size particle.

In some embodiments of the porous catalytic material, the catalytic nanoparticle comprises at least one platinum group metal. In some embodiments, the catalytic nanoparticle comprises rhodium. In some embodiments, the catalytic nanoparticle comprises platinum or palladium. In some embodiments, the catalytic nanoparticle comprises platinum and palladium. In some embodiments, the catalytic

nanoparticle comprises platinum and palladium in a weight ratio of about 1 :2 platinum : palladium to about 25 : 1 platinum : palladium. In some embodiments, the catalytic nanoparticle comprises platinum and palladium in a weight ratio of about 2: 1 platinum : palladium to about 10 : 1 platinum : palladium. In some embodiments, the catalytic nanoparticle comprises platinum and palladium in a weight ratio of 2: 1 platinum : palladium. In some embodiments, the catalytic nanoparticle comprises platinum and palladium in a weight ratio of 10 : 1 platinum : palladium. In some embodiments, the catalytic nanoparticle comprises platinum and is substantially free of palladium. In some embodiments, the catalytic nanoparticle comprises palladium and is substantially free of platinum. In some embodiments, the composite nanoparticles comprise about 10 wt% to 70 wt% catalytic metal . In some embodiments, the composite nanoparticles comprise about 30 wt% to 50 wt% platinum group metal. In some embodiments, the catalytic nanoparticle has a diameter between 1 nm and 10 nm. In some embodiments of the porous catalytic material, the support nanoparticle comprises a metal oxide. In some embodiments, the support nanoparticle has a diameter of 10 nm to 20 nm . In some embodiments, the support nanoparticle comprises aluminum oxide, cerium oxide, zirconium oxide, lanthanum oxide, yttrium oxide, silica, neodymium oxide, or a combination thereof. In some embodiments, the support nanoparticle comprises aluminum oxide and the catalytic material comprises platinum or palladium . In some embodiments, the support nanoparticle comprises cerium oxide and the catalytic particle comprises rhodium . In some embodiments of the porous catalytic material, the spacer nanoparticles comprise a metal oxide. In some embodiments, the spacer nanoparticles comprises aluminum oxide, cerium oxide, zirconium oxide, lanthanum oxide, yttrium oxide, silica, neodymium oxide, or a combination thereof. In some embodiments, the support nanoparticle and the spacer nanoparticles are the same material . In some embodiments, the spacer nanoparticles and the porous carrier comprise the same material .

In some embodiments of the porous catalytic material, the porous carrier comprises a metal oxide. In some embodiments, the porous carrier comprises aluminum oxide, cerium oxide, zirconium oxide, lanthanum oxide, yttrium oxide, silica, neodymium oxide, or a combination thereof. In some embodiments, the porous carrier comprises aluminum oxide, the spacer nanoparticles comprise aluminum oxide, the support nanoparticle comprises aluminum oxide, and the catalytic material comprises platinum or palladium . In some embodiments, the porous carrier further comprises lanthanum oxide. In some embodiments, the porous carrier comprises cerium oxide, the spacer nanoparticles comprise cerium oxide, the support nanoparticle comprises cerium oxide, and the catalytic particle comprises rhodium .

In some embodiments of the porous catalytic material, the catalytic material has a BET surface area of about 200 m2/g or more. In some embodiments, the catalytic material has an average pore diameter of about 1 nm to about 200 nm . In some embodiments, the plurality of the composite nanoparticles and the plurality of non- catalytic spacer nanoparticles are present in the catalytic material at a ratio of about 1 : 1 to about 1 : 50. In some embodiments, the catalytic material comprises about 1 wt% to about 7 wt% platinum group metal . In another aspect, there is provided a method of producing a porous catalytic material comprising mixing a plu rality of composite nanoparticles and a plurality of non-catalytic spacer nanoparticles with a liquid comprising a carrier precursor, wherein the composite nanoparticles comprise a su pport nanoparticle and a catalytic nanoparticle; solidifying the carrier precursor to form a solidified carrier that bridges together the plurality of composite nanoparticles and the plurality of spacer nanoparticles; and removing a portion of the solidified carrier to form the porous catalytic material . In some embodiments, the carrier precu rsor is solidified to form a combustible component of the solidified carrier and a non-combustible component of the solidified carrier, and the combustible component of the solidified carrier is removed to form the porous catalytic material . In some embodiments, the combustible component of the solidified carrier is removed by calcining the sol idified carrier.

In some embodiments, the method of forming a porous catalytic material comprises mixing a pl urality of composite nanoparticles and a plurality of non-cata lytic spacer nanoparticles prior to mixing the plurality of composite nanoparticles and the plurality of non-cata lytic spacer nanoparticles with the liquid containing the carrier precursor.

In some embodiments, the method of forming a porous catalytic material comprises stabilizing the carrier with a stabilizing metal oxide . In some embodiments, the stabilizing metal oxide is lanthanum oxide . In some embodiments, the carrier is stabilized by applying a stabilizing metal oxide precu rsor solution to the catalytic material, drying the catalytic material, and calcin ing the catalytic material .

In some embodiments of the method of forming a porous catalytic material, the sol idified carrier comprises aluminum oxide, cerium oxide, zirconium oxide, lanthanum oxide, yttriu m oxide, silica, or a combination thereof. In some embodiments, the solidified carrier comprises aluminum oxide and lanthanum oxide.

In some embodiments of a method of forming a porous catalytic material, the carrier precursor comprises a combustible component comprising resorcinol . In some embodiments, the carrier precursor further comprising a crosslinking agent. In some embodiments, the carrier precursor comprises formaldehyde and

propylene oxide.

In some embodiments of a method of forming a porous catalytic material, the carrier precursor is solidified by polymerization.

In some embodiments of the method of forming a porous catalytic material, the catalytic nanoparticle comprises at least one platinum group metal . In some embodiments, the catalytic nanoparticle comprises rhodium. In some embodiments, the catalytic nanoparticle comprises platinum or palladium. In some embodiments, the catalytic nanoparticle comprises platinum and palladium. In some

embodiments, the catalytic nanoparticle comprises platinum and palladium in a weight ratio of about 1 :2 platinum : palladium to about 25 : 1 platinum : palladium. In some embodiments, the catalytic nanoparticle comprises platinum and palladium in a weight ratio of about 2: 1 platinum : palladium to about 10 : 1 platinum : palladium. In some embodiments, the catalytic nanoparticle comprises platinum and is substantially free of palladium. In some embodiments, the catalytic nanoparticle comprises palladium and is substantially free of platinum. In some embodiments, the composite nanoparticles comprise about 10 wt% to 70 wt% platinum group metal. In some embodiments, the composite nanoparticles comprise about 30 wt% to 50 wt% platinum group metal. In some embodiments, the catalytic nanoparticle has an average diameter between 1 nm and 10 nm.

In some embodiments of the method of forming a porous catalytic material, the support nanoparticle comprises a metal oxide. In some embodiments, the support nanoparticle has an average diameter of 10 nm to 20 nm. In some embodiments, the support nanoparticle comprises aluminum oxide, cerium oxide, zirconium oxide, lanthanum oxide, yttrium oxide, silica, or a combination thereof. In some embodiments, the support nanoparticle comprises aluminum oxide and the catalytic material comprises platinum or palladium . In some embodiments, the support nanoparticle comprises cerium oxide and the catalytic particle comprises rhodium . In some embodiments of a method of forming a porous catalytic material, the composite nanoparticles and the spacer nanoparticles are present in the catalytic material at a ratio of about 1 : 1 to about 1 : 50.

In some embodiments of the method of forming a porous catalytic material, the spacer nanoparticles comprise a metal oxide. In some embodiments, the spacer nanoparticles comprise aluminum oxide, cerium oxide, zirconium oxide, lanthanum oxide, yttrium oxide, silica, or a combination thereof. In some embodiments, the spacer nanoparticles comprise aluminum oxide. In some embodiments, the support nanoparticle and the spacer nanoparticles are the same material . In some embodiments, the spacer nanoparticles and the porous carrier comprise the same material . In some embodiments, the spacer nanoparticles comprise boehmite. In some embodiments of the method of forming a porous catalytic material, the porous catalytic material comprises about 1 wt% to about 7 wt% platinum group metal .

In some embodiments, the method of forming the porous catalytic material comprises processing the resulting catalytic material into micron-sized particles. In some embodiments, the resulting catalytic material is ground to form micron-sized particles.

In another aspect, there is provided a coated substrate comprising a substrate and a washcoat layer comprising the catalytic material described above, or a catalytic material made according to the method described above. In some embodiments, the substrate comprises cordierite. In some embodiments, the substrate comprises a honeycomb structure. Further provided herein, there is a catalytic converter comprising the coated substrate. Also provided herein is an exhaust treatment system comprising a conduit for exhaust gas and the catalytic converter. Also described herein is a vehicle comprising the coated substrate, the catalytic converter, or the exhaust treatment system.

In another aspect, there is provided a washcoat composition comprising the catalytic material described above. In some embodiments, the washcoat

composition comprises aqueous medium at a pH between 3 and 5. In some embodiments, there is provided a method of forming a coated substrate comprising coating a substrate with the washcoat composition. In some embodiments, the method further comprises calcining the substrate after coating with the washcoat composition.

In another aspect, there is provided herein a catalytic material comprising a plurality of composite nanoparticles comprising a support nanoparticle and a catalytic nanoparticle; a plurality of non-catalytic spacer nanoparticles; and a carrier that bridges together the composite nanoparticles and the spacer

nanoparticles, wherein the carrier comprises a combustible component and a non-combustible component. In some embodiments, the combustible component comprises a combustible gel. In some embodiments, the combustible component comprises polymerized resorcinol .

In some embodiments of the catalytic material, the catalytic nanoparticle comprises at least one platinum group metal. In some embodiments, the catalytic nanoparticle comprises rhodium. In some embodiments, the catalytic nanoparticle comprises platinum or palladium. In some embodiments, the catalytic nanoparticle comprises platinum and palladium. In some embodiments, the catalytic nanoparticle comprises platinum and palladium in a weight ratio of about 1 : 2 platinum :

palladium to about 25 : 1 platinum : palladium. In some embodiments, the catalytic nanoparticle comprises platinum and palladium in a weight ratio of about 2: 1 platinum : palladium to about 10 : 1 platinum : palladium. In some embodiments, the catalytic nanoparticle comprises platinum and is substantially free of palladium. In some embodiments, the catalytic nanoparticle comprises palladium and is substantially free of platinum . In some embodiments, the composite nanoparticles comprise about 10 wt% to 70 wt% platinum group metal . In some embodiments, the composite nanoparticles comprise about 30 wt% to 50 wt% platinum group metal . In some embodiments, the catalytic nanoparticle has an average diameter between 1 nm and 10 nm .

In some embodiments of the catalytic material, the support nanoparticle comprises a metal oxide. In some embodiments, the support nanoparticle comprises aluminum oxide, cerium oxide, zirconium oxide, lanthanum oxide, yttrium oxide, silica, or a combination thereof. In some embodiments, the support nanoparticle has an average diameter of 10 nm to 20 nm . In some embodiments, the support nanoparticle comprises aluminum oxide and the catalytic material comprises platinum or palladium . In some embodiments, the support nanoparticle comprises cerium oxide and the catalytic particle comprises rhodium .

In some embodiments of the catalytic material, the non-combustible component of the carrier comprises a metal oxide. In some embodiments, the non-combustible component of the carrier comprises aluminum oxide, cerium oxide, zirconium oxide, lanthanum oxide, yttrium oxide, silica, or a combination thereof. In some

embodiments, the non-combustible component of the carrier comprises aluminum oxide, the support nanoparticle comprises aluminum oxide, and the catalytic material comprises platinum or palladium . In some embodiments, the non- combustible component of the carrier further comprises lanthanum oxide. In some embodiments, the porous carrier comprises cerium oxide, the support nanoparticle comprises cerium oxide and the catalytic particle comprises rhodium . In some embodiments, the composite nanoparticles and the plurality of spacer nanoparticles are present in the catalytic material at a ratio of about 1 : 1 to about 1 : 50. In some embodiments, the catalytic material comprises about 1 wt% to about 7 wt% platinum group metal

In another aspect, there is provided a method of producing a catalytic material comprising mixing a plurality of composite nanoparticles and a plurality of non- catalytic spacer nanoparticles with a liqu id comprising a carrier precursor, wherein the composite nanoparticles comprise a support nanoparticle and a catalytic nanoparticle; and sol idifying the carrier precursor to form a sol idified carrier that bridges together the composite nanoparticles and the non-catalytic spacer nanoparticles. In some embodiments, the method fu rther comprises mixing a plurality of composite nanoparticles and a plurality of non-catalytic spacer nanoparticles prior to mixing the plurality of composite nanoparticles and the plurality of non-cata lytic spacer nanoparticles with the liquid containing the carrier precursor. In some embodiments, the carrier precursor is solidified to form a combustible component of the solidified carrier and a non-combustible component of the solidified carrier.

In some embodiments, the method of forming the catalytic material comprises stabilizing the carrier with a stabilizing metal oxide . In some embodiments, the stabilizing metal oxide is lanthanum oxide . In some embodiments, carrier is stabil ized by adding a stabilizing metal oxide precursor solution to the catalytic material, drying the catalytic material, and calcining the catalytic material .

In some embodiments of the method of making the catalytic material, the non- combustible component comprises aluminum oxide, ceriu m oxide, zircon ium oxide, lanthanum oxide, yttriu m oxide, silica, or a combination thereof. In some embodiments, the non-combustible component comprises aluminum oxide and lanthan um oxide .

In some embodiments of the method of making the catalytic material, the carrier precursor is solidified by polymerization . In some embodiments, the combustible component comprises a combustible gel . In some embodiments, the combustible component comprises polymerized resorcinol .

In some embodiments of the method of making the catalytic material, the catalytic nanoparticle comprises at least one platinu m group metal . In some embodiments, the catalytic nanoparticle comprises rhodium . In some embodiments, the catalytic nanoparticle comprises platinum or palladium . In some embodiments, the catalytic nanoparticle comprises platinum and palladium . In some embodiments, the catalytic nanoparticle comprises platinum and palladium in a weight ratio of about 1 : 2 platinum : palladium to about 25 : 1 platinum : palladium. In some embodiments, the catalytic nanoparticle comprises platinum and palladium in a weight ratio of about 2 : 1 platinum : palladium to about 10 : 1 platinum : palladium. In some embodiments, the catalytic nanoparticle comprises platinum and is substantially free of palladium. In some embodiments, the catalytic nanoparticle comprises palladium and is substantially free of platinum. In some embodiments, the composite nanoparticles comprise about 10 wt% to 70 wt% platinum group metal . In some embodiments, the composite nanoparticles comprise about 30 wt% to 50 wt% platinum group metal. In some embodiments, the catalytic nanoparticle has an average diameter between 1 nm and 10 nm.

In some embodiments of the method of making the catalytic material, the support nanoparticle comprises a metal oxide. In some embodiments, the support nanoparticle comprises aluminum oxide, cerium oxide, zirconium oxide, lanthanum oxide, yttrium oxide, silica, or a combination thereof. In some embodiments, the support nanoparticle has an average diameter of 10 nm to 20 nm. In some embodiments, the support nanoparticle comprises aluminum oxide and the catalytic material comprises platinum or palladium. In some embodiments, the support nanoparticle comprises cerium oxide and the catalytic particle comprises rhodium. In some embodiments of the method of making the catalytic material, the plurality of composite nanoparticles and the plurality of non-catalytic spacer nanoparticles are present in the catalytic material at a ratio of about 1 : 1 to about 1 : 50. In some embodiments, the catalytic material comprises about 1 wt% to about 7 wt% platinum group metal.

DETAILED DESCRIPTION OF THE INVENTION

Described herein are catalytic particles, washcoats, coated substrates, and catalytic converters that include catalytic materials. The catalytic materials include composite nanoparticles, which include a support nanoparticle and a catalytic nanoparticle, and spacer nanoparticles that are substantially free or free from a catalytic metal, wherein the composite nanoparticles and the spacer nanoparticles are bridged together by a porous carrier. The catalytic materials can be in the form of bulk catalytic material or micron-sized particles. Also described are methods of making and using these materials.

It has been found that described catalytic materials provide for increased

performance, illustrated, for example, by decreased carbon monoxide "light-off" temperatures and decreased platinum group metal loading, relative to prior catalysts such as catalysts prepared using wet-chemistry methods or other technologies using nanoparticles. For example, previous catalytic materials can include a catalytic metal, such as a platinum group metal, deposited on micron- sized metal oxide particles by wet-chemistry methods. The catalytic metals deposited by wet chemistry exhibit mobility during increased temperatures, causing agglomeration of the catalytic metal, which reduces the ratio of the available catalytic surface to catalytic metal weight, and the catalytic efficiency of the material. The effect of catalytic agglomeration in catalytic converters is often referred to as "aging," and can be measured by reduced efficiency of the catalytic converter after use. It has been found that a catalytic material comprising composite nanoparticles (which include a support nanoparticle and a catalytic nanoparticle) and spacer nanoparticles (which are substantially free from a catalytic metal) that are bridged together by a porous carrier exhibit limit agglomeration of the catalytic metal, which allows for increased longevity of the catalytic material at elevated temperatures.

The catalytic material can include a porous carrier that bridges together the composite nanoparticles and spacer nanoparticles, which allows fluids to be treated, such as an exhaust gas, to slowly flow through the pores of the porous carrier and contact very high surface area of the catalytic particles embedded within the porous carrier. This high surface allows for catalysis that is more efficient, for example by requiring lower amounts of platinum group metals. The porous carrier also locks the composite nanoparticles and the support nanoparticles in place to reduce

agglomeration of the catalytic particles. Further, the inclusion of spacer nanoparticles reduces the likelihood that a catalytic metal from the composite nanoparticle will collide with catalytic metal from other composite nanoparticles in the catalytic material . The carrier can be formed around the composite

nanoparticles and the support nanoparticles, in contrast to methods using pre- formed porous carrier particles as carriers for the composite nanoparticles. The carrier can include a combustible component and a non-combustible component. When the combustible component is removed (for example by calcining the catalytic material to burn off the combustible component) the resulting non- combustible component remains as a porous carrier that bridges the composite nanoparticles and the spacer nanoparticles together.

As described herein, the catalytic material can be processed into micron-sized catalytic particles. This configuration offers many advantages over micron-sized particles bearing composite nanoparticles just on the surface of or within the surface-accessible pores of pre-formed micron-sized carrier particles (the surface- accessible pores are the pores of the micron-sized carrier particle that are large enough to accept the composite nanoparticles, and which are accessible to the composite nanoparticles from the surface) . In technologies using micron-sized carrier particles bearing composite nanoparticles on the surface or within surface- accessible pores of the micron-sized particles, a slurry of composite nanoparticles is generally applied to pre-formed micron-sized particles, for example commercially available micron-sized metal oxide particles, until the point of incipient wetness. That process impregnates composite nanoparticles on the surface of the micron- sized carrier particle and within pores of the micron-sized carrier particle that are large enough to accept the composite nanoparticles (the surface-accessible pores) . Furthermore, when applying composite nanoparticles only onto the surface of a micron-sized carrier particle, some composite nanoparticles may be buried underneath other composite nanoparticles within the pores of the micron particle and, thus, inaccessible to target gases and unable to contribute to catalytic activity. In some embodiments, composite nanoparticles bridged together by the carrier are produced by mixing composite nanoparticles, such as those described in US 2011/0143915 with a fluid comprising a carrier precursor. The carrier precursor is then solidified, for example by polymerization of the carrier precursor components, locking the composite nanoparticles within the carrier. In some embodiments, a portion of the carrier is removed, thereby resulting in a porous carrier. The high porosity of the carrier ensures that gases flowing through the carrier are able to contact the catalytic nanoparticles. In some embodiments, the carrier precursor comprises a combustible component, for example a polymerized organic gel (such as polymerized resorcinol), and a non-combustible component, such as a metal oxide (for example one or more of aluminum oxide, cerium oxide, lanthanum oxide, zirconium oxide, yttrium oxide, or a combination thereof) . In some embodiments, the carrier precursor comprises a combustible component, for example a

polymerized organic gel or amorphous carbon, and a non-combustible component, such as a precursor to a metal oxide, for example aluminum nitrate, cerium nitrate, zirconium acetate, zirconium nitrate, zirconium oxynitrate, neodymium nitrate, lanthanum acetate, or yttrium nitrate. In some embodiments, a portion of the solidified carrier, for example the combustible component, is removed, for example, by calcining the material, resulting in composite nanoparticles embedded within a porous carrier. In some embodiments, the resulting catalytic material is processed into micron-sized particles.

Catalytic particles can be used in many catalytic applications. For example, in some embodiments, the catalytic particles may be used in washcoat formulations that can be coated on catalytic substrates used to make catalytic converters. Coated substrates and catalytic converters using catalytic particles efficiently catalyze exhaust gas emitted by vehicles.

Composite nanoparticles used to produce catalytic particles include a catalytic nanoparticle and a support nanoparticle bonded together to form nano-on-nano composite nanoparticles. These composite nanoparticles may be bridged together by a porous carrier which is formed around the composite nanoparticles, which may be used to form micron-sized catalytic particles. The composite nanoparticles may be produced, for example, in a plasma reactor in such a way that consistent nano- on-nano composite particles are produced. The catalytic particles offer better performance over the lifetime of the catalyst and/or less reduction in performance over the life of the catalyst as compared to previous catalysts, such as catalysts prepared using wet-chemistry methods or other nanoparticle technologies, such as those using composite nanoparticles disposed on the surface of micron-sized particles.

Definitions

As used herein, the singular forms "a," "an," and "the" include the plural reference unless the context clearly dictates otherwise.

Reference to "about" a value or parameter herein includes (and describes) variations that are directed to that value or parameter per se. For example, description referring to "about X" includes description of "X".

The term "bridged together" or "embedded" when describing nanoparticles bridged together or "embedded" by a carrier, refers to the configuration of the

nanoparticles in the carrier resulting when the carrier is formed around the nanoparticles, generally by using the methods described herein. That is, the resulting structure contains nanoparticles with a scaffolding of porous carrier built up around or surrounding the nanoparticles. The porous carrier encompasses the nanoparticles, while at the same time, by virtue of its porosity, the porous carrier permits external gases to contact the nanoparticles.

The term "diameter" when referring to a particle size is used synonymously with the term "grain size" as understood by the ASTM (American Society for Testing and Materials) standard (see ASTM E112-10). When calculating a diameter of a particle, the average of its longest and shortest dimension is taken; thus, the diameter of an ovoid particle with long axis 20 nm and short axis 10 nm would be 15 nm. The average diameter of a population of particles is the average of diameters of the individual particles, and can be measured by various techniques known to those of skill in the art. It is generally understood by one of skill in the art that the unit of measure "g/l" or "grams per liter" is used as a measure of density of a substance in terms of the mass of the substance in any given volume containing that substance. When referring to a thickness of a washcoat or washcoat layer coated on a substrate, or when referring to the amount of washcoat loaded onto a substrate (WC load), "g/l" is used to refer to the mass of solids in the washcoat or washcoat layer per the volume of the substrate. When referring to an amount of material "loaded" onto a substrate, "g/l" is used to refer to the mass of that material per the volume of the substrate. For example, "platinum loaded onto a substrate at 4.0 g/l" refers to 4.0 grams of platinum for each liter of a coated substrate. Similarly, "a washcoat layer thickness of 100 g/l" refers to a washcoat layer having 100 grams of solids for each liter of the coated substrate.

The terms "micro-particle," "micro-sized particle," "micron-particle," and "micron- sized particle" refer to a particle with a diameter between about 0.5 micrometers and about 1000 micrometers.

The terms "nanoparticle" and "nano-sized particle" refer to a particle with a diameter between about 0.5 nm and about 500 nm.

A "non-catalytic" material refers to a material that does not catalyze the oxidation or reduction of hydrocarbons, carbon monoxide, or a nitrogen oxide.

The term "platinum group metals" (abbreviated "PGM") refers to the collective name for the metals ruthenium, rhodium, palladium, osmium, iridium, and platinum.

This disclosure refers to both particles and powders. These two terms are

equivalent, except for the caveat that a singular "powder" refers to a collection of particles. The present invention can apply to a wide variety of powders and particles.

The word "substantially" does not exclude "completely." For example, a composition which is "substantially free" from Y may be completely free from Y. The term "substantially free" permits trace or naturally occurring impurities. It should be noted that, during fabrication, or during operation (particularly over long periods of time), small amounts of materials present in one washcoat layer may diffuse, migrate, or otherwise move into other washcoat layers. Accordingly, use of the terms "substantial absence of" and "substantially free of" is not to be construed as absolutely excluding minor amounts of the materials referenced. Where necessary, the word "substantially" may be omitted from the definition of the invention .

"Treating" an exhaust gas refers to having the exhaust gas proceed through an exhaust system, thereby catalyzing at least a portion of the gasses in the exhaust gas into some other chemical form prior to release into the environment.

A "washcoat composition" refers to a suspension of one or more solid components, such as particles, in a liquid . The washcoat composition can also include one or more salts dissolved in the liquid. A "washcoat layer" refers to a washcoat composition after the composition has been applied to a substrate, either before or after the washcoat composition has been dried or calcined .

The term "wet-chemistry method" is used herein to describe any technique whereby a solution of a metal salt is deposited on or in a material, and the metal salt is converted into a metallic form .

The term "wt%" is used herein to refer to a weight percentage. Weight percentages of materials in a solution or suspension (such as a washcoat composition) refer to the weight percentages of solids in that solution or suspension after removing liquid components. Salts (such as barium salts) or other materials dissolved in the liquid are included as solids if the salts or other materials would be solids upon

evaporation of the liquid .

It shou ld be noted that, during fabrication or during operation (particularly over long periods of time), small amounts of materials present in one layer may diffuse, migrate, or otherwise move into other layers.

It is understood that reference to relative weight percentages in a composition assumes that the combined total weight percentages of all components in the composition add up to 100. It is further understood that relative weight

percentages of one or more components may be adjusted upwards or downwards such that the weight percent of the components in the composition combine to a total of 100, provided that the weight percent of any particular component does not fall outside the limits of the range specified for that component.

Various aspects of the disclosure can be described through the use of flowcharts. Often, a single instance of an aspect of the present disclosure is shown . As is appreciated by those of ordinary skill in the art, however, the protocols, processes, and procedures described herein can be repeated continuously or as often as necessary to satisfy the needs described herein . In addition, it is contemplated that certain method steps can be performed in alternative sequences to those disclosed in the flowcharts.

This disclosure provides several examples and embodiments. It is contemplated that any features from any embodiment can be combined with any features from any other embodiment where possible. In this fashion, hybrid configurations of the disclosed features are within the scope of the present invention .

The disclosures of all publications, patents, and patent applications referred to herein are each hereby incorporated herein by reference in their entireties. To the extent that any reference incorporated by references conflicts with the instant disclosure, the instant disclosure shall control .

Composite Nanoparticles

The catalytic material described herein includes composite nanoparticles. The composite nanoparticles include a catalytic nanoparticle attached to a support nanoparticle. As the catalytic nanoparticle is attached to the support nanoparticle, the composite nanoparticle can also be referred to as a "nano-on-nano" particle.

The catalytic nanoparticle includes a catalytic metal, such as a platinum group metal . The support nanoparticle can include a metal oxide, which may be the same or different from a metal oxide of the carrier. The configuration of the catalytic nanoparticle on the support nanoparticle

In some embodiments, the catalytic nanoparticle comprises one or more platinum group metals, such as rhodium, platinum, or palladium. In some embodiments, the catalytic nanoparticle includes a catalytic metal alloy, such as a platinum-palladium alloy, and in some embodiments the catalytic nanoparticle comprises a homogenous metal. The alloy metals may be found in any ratio, such as about 1 : 1 platinum : palladium by weight to about 50 : 1 platinum : palladium by weight (such as about 2 : 1 platinum : palladium to about 25 : 1 platinum : palladium, or about 2: 1 platinum : palladium to about 10 : 1 platinum : palladium) . In some embodiments, the ratio of platinum to palladium is about 1 : 50 platinum : palladium, about 1 :25 platinum : palladium, about 1 : 10 platinum : palladium, or about 1 : 2

platinum : palladium. In some embodiments, the catalytic nanoparticle comprises platinum and is substantially free of palladium. In some embodiments, the catalytic nanoparticle comprises palladium but is substantially free of platinum.

The composite nanoparticles include one or more nano-sized catalytic particles disposed on a nano-sized support particle. The support nanoparticle can be a refractory material, such as a metal oxide or a mixed metal oxide. By way of example, oxides such as alumina (AI2O3), silica (S1O2), zirconia (ZrCh), ceria

(cerium oxide, CeCh), lanthana (La ₂ 03), and yttria (Y2O3) . In some embodiments, the support nanoparticle comprises a mixture of alumina and lanthana. In some embodiments, the support nanoparticle comprises a mixture of ceria and zirconia; a mixture of ceria and lanthana; a mixture of ceria and yttria; a mixture of ceria, zirconia, and lanthana; a mixture of ceria, zirconia, and yttria; or a mixture of ceria, zirconia, lanthana and yttria. Other useful oxides will be apparent to those of ordinary skill.

The composite nanoparticles can include a catalytic nanoparticle and a support nanoparticle of particular types to obtain a desired catalytic effect. For example, in some embodiments, a reducing composite nanoparticle comprises a catalytic nanoparticle comprising rhodium and the support nanoparticle comprising ceria (which may further comprise lanthana and/or yttria) or a mixture of ceria and zirconia (which may further comprise lanthana and/or yttria). In some

embodiments, an oxidizing composite nanoparticle comprises a catalytic

nanoparticle comprising platinum and/or palladium and a support nanoparticle comprising alumina (which may further comprise lanthana) . In some embodiments, the amount of catalytic metal (located in the catalytic nanoparticle) in the composite nanoparticle can range from about 1 wt% to about 80 wt% of the composite nanoparticle (such as about 5 wt% to about 75wt%, about 10 wt% to about 70 wt%, about 20 wt% to about 60 wt%, about 30 wt% to about 50 wt%, or about 40 wt%) . The balance of the composite nanoparticle can be material in the support nanoparticle (such as the metal oxide). That is, in some embodiments, the support material (located in the support nanoparticle) in the composite nanoparticle ranges from about 20 wt% to about 99 wt% of the composite nanoparticle (such as about 25 wt% to about 95 wt%, about 30 wt% to about 90 wt%, about 40 wt% to about 80 wt%, about 50 wt% to about 70 wt%, or about 60 wt%).

In some embodiments, diameter of the catalytic nanoparticle in the composite nanoparticle is between about 1 nm and about 10 nm (such as between about 2 nm and about 8 nm, between about 3 nm and about 7 nm, between about 4 nm and about 6 nm, or about 5 nm). In some embodiments, the diameter of the support nanoparticle in the composite nanoparticle is between about 10 nm and about 20 nm (such as between about 12 nm and about 18 nm, about 14 nm and about 16 nm, or about 15 nm). A plurality of composite nanoparticles may have some variance (i.e., a distribution) in the size of the catalytic particles or support particles in the plurality. Accordingly, the size of the catalytic nanoparticle or the support particle can be described as an average diameter. That is, in some embodiments, the average diameter of the catalytic nanoparticles in a plurality of composite nanoparticles is between about 1 nm and about 10 nm (such as between about 2 nm and about 8 nm, between about 3 nm and about 7 nm, between about 4 nm and about 6 nm, or about 5 nm). In some embodiments, the average diameter of the support nanoparticles in the plurality of composite nanoparticles is between about 10 nm and about 20 nm (such as between about 12 nm and about 18 nm, about 14 nm and about 16 nm, or about 15 nm).

In some embodiments, the composite nanoparticles are formed by plasma based methods. For example, the composite nanoparticles can be formed by feeding one or more catalytic metals (which is used to form the catalytic nanoparticles) and one or more support materials (which is used to form the support nanoparticles) into a plasma gun. In some embodiments, the catalytic metal provided in the form of metal particles (such as about 0.5 to 6 micrometers in diameter), and can be introduced into the plasma reactor as a fluidized powder in a carrier gas stream. In some embodiments two or more different catalytic metals may be added in any desired ratio useful for obtaining an alloy for the catalytic nanoparticle. For example, in some embodiments a mixture of platinum and palladium is added at a ratio of about 1 : 1 platinum : palladium by weight to about 50 : 1 platinum : palladium by weight (such as about 2 : 1 platinum : palladium to about 25 : 1 platinum :

palladium, or about 2: 1 platinum : palladium to about 10 : 1 platinum : palladium) . Support material in the form of particles (such as about 15 to 25 micro meters in diameter) can also be introduced as a fluidized powder in carrier gas. The ratio of catalytic metal to support material can be selected based on the proportions of the resulting composite nanoparticles. Once in the plasma gun, the materials are vaporized. A working gas (such as an inert gas (e.g., argon), which may be mixed with a reducing gas (such as hydrogen)) is supplied to the plasm gas to carry the input materials. Although material is preferably provided to the plasma reactor as a powder, other methods of introducing the materials into the reactor can be used, such as in a liquid slurry. Any solid or liquid materials are rapidly vaporized or turned into plasma. The kinetic energy of the vaporized material, which can reach temperatures of 20,000 to 30,000 Kelvin, ensures extremely thorough mixing of all components. The vaporized catalytic metal and support materials are quenched (for example, using such methods as the turbulent quench chamber disclosed in US 2008/0277267) by injecting a quench gas (e.g., an inert gas such as argon) into the system, resulting in the formation of the composite nanoparticles. The quench gas is preferably provided at high flow rates, such as 2400 to 2600 liters per minute, and mixed with the vaporized material. The material is further cooled in a cool-down tube and collected. Optionally, the resulting composite nanoparticles are analyzed to ensure proper size ranges of material. Catalytic nanoparticles containing the catalytic metal are attached to support nanoparticles containing the support material. An exemplary high-throughput particle production system useful for forming the composite nanoparticles is described in US 2014/0263190 and International Patent Appl. No. PCT/US2014/02493. Other equipment suitable for plasma synthesis is disclosed in U.S. Patent Application Publication No.

2008/0277267 and U.S. Patent No. 8,663,571. Plasma guns such as those disclosed in US 2011/0143041 can be used, and techniques such as those disclosed in US 5,989,648, US 6,689,192, US 6,755,886, and US 2005/0233380 can be used to generate plasma.

The plasma production method described above produces uniform composite nanoparticles, where the composite nanoparticles comprise a catalytic nanoparticle disposed on a support nanoparticle.

Spacer Nanoparticles

In addition to the composite nanoparticles, the catalytic material described herein includes spacer nanoparticles. The spacer nanoparticles increases the average distance between composite nanopraticles by occupying space in the carrier material that would otherwise be occupied by composite nanoparticles. Increasing the distance between the composite nanoparticles using spacer particles can decrease the amount of catalytic metal agglomeration.

The spacer nanoparticles can be distinguished from the composite nanoparticles because the composite nanoparticles include a catalytic nanoparticle attached to a support nanoparticle, whereas the spacer nanoparticles do not include the catalytic nanoparticle. That is, in some embodiments, the spacer nanoparticles are preferably non-catalytic spacer nanoparticles. In some embodiments, the spacer nanoparticles are substantially free or free from a catalytic metal. Spacer nanoparticles that are substantially free from a catalytic metal may contain trace amounts of a catalytic metal as long as the amount of catalytic metal present on the spacer nanoparticle does not result in a significant change in catalytic efficiency or rate of catalytic metal agglomeration . In some embodiments, the spacer nanoparticles consist essentially of or consist of a refractory material . Spacer nanoparticles that consist essentially of a refractory material may contain other materials as long as the amount of other material present on the spacer

nanoparticle does not result in a significant change in catalytic efficiency or rate of catalytic metal agglomeration . A "refractory material" is any material with a melting temperature of 1980 °C or higher. In one embodiment, the refractory material can include one or more metal oxides, boron nitride, or silicon carbide. Two or more materials can be mixed together (e.g., a mixed-metal oxide) to form a refractory material even when one or both materials in isolation is not a refractory material . The spacer nanoparticles can be the same material or a different material as the porous carrier (or the non-combustible component of the carrier) . The spacer nanoparticles can also be the same material or a different material as the support nanoparticle of the composite nanoparticles. The spacer nanoparticle can be a refractory material, such as a metal oxide, a mixed metal oxide, boron nitride, or silicon carbide. By way of example, metal oxides such as one or more of alumina (AI203), silica (Si02), zirconia (Zr02), ceria (cerium oxide, Ce02), lanthana

(La203), and yttria (Y203) can be used. In some embodiments, the alumina is derived from boehmite, for example by including boehmite particles during the formation of the catalytic material and calcining the catalytic material. In some embodiments, the spacer nanoparticles comprise boehmite. In some embodiments, the spacer nanoparticle comprises a mixture of alumina and lanthana. In some embodiments, the spacer nanoparticle comprises a mixture of ceria and zirconia; a mixture of ceria and lanthana; a mixture of ceria and yttria; a mixture of ceria, zirconia, and lanthana; a mixture of ceria, zirconia, and yttria; or a mixture of ceria, zirconia, lanthana, and yttria. Other useful oxides will be apparent to those of ordinary skill.

In some embodiments, the average diameter of the spacer nanoparticles is between about 1 nm and about 100 nm (such as between about 2 nm and about 75 nm, between about 5 nm and about 50 nm, or between about 10 nm and about 20 nm). In some embodiments, the spacer nanoparticles are commercially available.

Exemplary commercially available spacer nanoparticles include AEROXIDE ^® Alu C (manufactured by Evonik, Germany) aluminum oxide particles. In some

embodiments, the spacer nanoparticles are plasma generated, for example by using micron-sized material into a nanoparticle production system (such as the system described for the manufacture of composite nanoparticles).

Catalytic Materials

The catalytic material includes a plurality of composite nanoparticles and a plurality of spacer nanoparticles that are bridged together by a carrier. In some

embodiments, the carrier is a porous carrier. In some embodiments, the carrier comprises a combustible component and a non-combustible component, and when the combustible component is removed, the remaining non-combustible component of the carrier is a porous carrier that bridges the composite nanoparticles and the spacer nanoparticles together. The catalytic material can be processed into micron- sized particles. Accordingly, in some embodiments, the catalytic material is micron- sized.

In some embodiments, there is provided a catalytic material comprising a plurality of composite nanoparticles (which include a support nanoparticle and a catalytic nanoparticle) and a plurality of spacer nanoparticles, wherein the plurality of composite nanoparticles and the plurality of spacer nanoparticles are bridged together by a porous carrier. The porous carrier acts as a three-dimensional scaffold to link the composite nanoparticles and the spacer nanoparticles. Spaces between the linking bridges in the scaffold act as pores, which allow gasses to flow through the catalytic material and contact the catalytic nanoparticles on the composite nanoparticles. Including the composite nanoparticles within the porous carrier results in a distinct advantage over those technologies where catalytically active nanoparticles are positioned on the surface of carrier micro-particles or do not penetrate as effectively into the pores of the support. When catalytically active nanoparticles are positioned on the surface of carrier micro-particles, some catalytically active nanoparticles can become buried by other catalytically active nanoparticles, causing them to be inaccessible to target gases because of the limited exposed surface area. When the composite nanoparticles are included within the porous carrier as described herein, gases can flow through the pores of the carrier to contact the catalytically active components.

The porous carrier may contain any large number of interconnected pores, holes, channels, or pits, preferably with an average pore, hole, channel, or pit width (diameter) ranging from 1 nm to about 200 nm, or about 1 nm to about 100 nm, or about 2 nm to about 50 nm, or about 3 nm to about 25 nm. In some embodiments, the porous carrier has a mean pore, hole, channel, or pit width (diameter) of less than about 1 nm, while in some embodiments, a porous carrier has a mean pore, hole, channel, or pit width (diameter) of greater than about 100 nm. In some embodiments, the catalytic material has a BET surface area in a range of about 50 m ² /g to about 500 m ² /g (such as about 100 m ² /g to about 400 m ² /g, or about 150 m ² /g to about 300 m ² /g) . In some embodiments, the catalytic material has a BET surface area of about 50 m ² /g or more (such as about 100 m ² /g or more, 150 m ² /g or more, 200 m ² /g or more, 250 m ² /g or more, 300 m ² /g or more, 400 m ² /g or more, or 500 m ² /g or more) .

In some embodiments, the porous carrier comprises the same material as the support nanoparticle or the spacer nanoparticle. In some embodiments, the porous carrier comprises a material different from the support nanoparticle or the spacer nanoparticle. In some embodiments, the porous carrier comprises a metal oxide, such as one or more of aluminum oxide, cerium oxide, zirconium oxide, lanthanum oxide, yttrium oxide, or silica. For example, in some embodiments the porous carrier comprises aluminum oxide and lanthanum oxide. In some embodiments, the porous carrier comprises cerium oxide (which optionally includes lanthanum oxide and/or yttrium oxide) or a mixture of cerium oxide and zirconium oxide (which optionally includes lanthanum oxide and/or yttrium oxide).

In another embodiment, there is provided a catalytic material comprising a plurality of composite nanoparticles (which include a support nanoparticle and a catalytic nanoparticle), a plurality of spacer nanoparticles, and a carrier that bridges together the plurality of composite nanoparticles and the plurality of spacer nanoparticles, wherein the carrier comprises a combustible component and a non- combustible component. The combustible component can be removed (for example, by calcining the catalytic material), leaving behind the non-combustible component which bridges together the composite nanoparticles and the spacer nanoparticles. The combustible component of the carrier filled spaces between the non- combustible component, and once removed results in pores in the carrier. That is, once the combustible carrier is removed, the non-combustible component is the porous carrier.

The combustible component of the carrier can be a combustible gel. For example, an organic material can be polymerized during the formation of the carrier, which can be the combustible component of the carrier. In some embodiments, the combustible component comprises polymerized resorcinol, which can be

polymerized using, for example, formaldehyde. The mixture of formaldehyde and resorcinol forms a combustible gel that can be burned out and exhausted at elevated temperatures (for example, by calcination).

The non-combustible component of the carrier can be the same material as the porous carrier (as once the combustible component of the carrier is removed, the remaining non-combustible component is the porous carrier) . In some

embodiments, the non-combustible component comprises a material different from the support nanoparticle or the spacer nanoparticle. In some embodiments, the non-combustible component comprises a metal oxide, such as one or more of aluminum oxide, cerium oxide, zirconium oxide, lanthanum oxide, yttrium oxide, or silica. For example, in some embodiments the non-combustible component comprises aluminum oxide and lanthanum oxide. In some embodiments, the non- combustible component comprises cerium oxide (which optionally includes lanthanum oxide and/or yttrium oxide) or a mixture of cerium oxide and zirconium oxide (which optionally includes lanthanum oxide and/or yttrium oxide). The catalytic material includes both composite nanoparticles and spacer nanoparticles. In some embodiments, the composite nanoparticles and the spacer nanoparticles are present in the catalytic material at a ratio of about 2:1 to about 1:50 (such as about 1:1 to about 1:25, about 1:1 to about 1:10, about 1:2 to about 1:8, about 1:3 to about 1:7, or about 1:4 to about 1:6). In some

embodiments, the composite nanoparticles and the spacer nanoparticles are present in the catalytic material at a ratio of about 2:1 or less (such as about 1:1 or less, about 1:2 or less, about 1:3 or less, about 1:4 or less, about 1:6 or less, about 1:7 or less, about 1:8 or less, about 1:10 or less, or about 1:25 or less). In some embodiments, the composite nanoparticles and the spacer nanoparticles are present in the catalytic material at a ratio of about 1:50 or more (such as about 1:25 or more, about 1:10 or more, about 1:8 or more, about 1:7 or more, about 1:6 or more, about 1:4 or more, about 1:3 or more, about 1:2 or more, or about 1:1 or more).

In some embodiments, the catalytic material comprises about 1 wt% to about 7 wt% catalytic metal (such as platinum group metal). For example, in some embodiments, the catalytic material comprises about 1.5 wt% to about 6 wt%, about 2 wt% to about 4 wt%, about 2.5 wt% to about 3.5 wt%, or about 3 wt% catalytic metal.

In some embodiments, the catalytic material is in the form of particles, such as micron-sized particles. For example, in some embodiments, the catalytic material has a diameter or average diameter between about 1 micrometer and about 250 micrometer (such as between about 1 micrometer and about 100 micrometer, about 2 micrometers and about 50 micrometers, between about 3 micrometers and about 25 micrometers, between about 4 micrometers and about 10 micrometers, or between about 5 micrometers and about 7 micrometers). In some embodiments, the catalytic material is in the form of particles with a diameter or average diameter of about 100 micrometers or less (such as about 50 micrometers or less, about 25 micrometers or less, about 20 micrometers or less, about 15 micrometers or less, about 10 micrometers or less, about 8 micrometers or less, about 7 micrometers or less, or about 5 micrometers or less).

In one embodiment of the catalytic material, the catalytic material comprises a plurality of composite nanoparticles comprising a support nanoparticle and a catalytic nanoparticle; a plurality of non-catalytic spacer nanoparticles; and a porous carrier that bridges together the plurality of composite nanoparticles and the plurality of spacer nanoparticles. The catalytic material can be a micron-size particle. In some embodiments, the catalytic material comprises about 1 wt% to about 7 wt% platinum group metal. In some embodiments, the plurality of the composite nanoparticles and the plurality of non-catalytic spacer nanoparticles are present in the catalytic material at a ratio of about 1 : 1 to about 1 : 50.

In some embodiments of the catalytic material, the catalytic material comprises a plurality of composite nanoparticles comprising a support nanoparticle and a catalytic nanoparticle comprising at least one platinum group metal (such as platinum, palladium, rhodium, or an alloy thereof, for example a mixture of platinum and palladium); a plurality of non-catalytic spacer nanoparticles; and a porous carrier that bridges together the plurality of composite nanoparticles and the plurality of spacer nanoparticles. The catalytic material can be a micron-size particle. In some embodiments, the catalytic material comprises about 1 wt% to about 7 wt% platinum group metal. In some embodiments, the plurality of the composite nanoparticles and the plurality of non-catalytic spacer nanoparticles are present in the catalytic material at a ratio of about 1 : 1 to about 1 : 50.

In some embodiments of the catalytic material, the catalytic material comprises a plurality of composite nanoparticles comprising a support nanoparticle comprising alumina and a catalytic nanoparticle comprising platinum, palladium, or a mixture thereof); a plurality of non-catalytic spacer nanoparticles; and a porous carrier that bridges together the plurality of composite nanoparticles and the plurality of spacer nanoparticles. The catalytic material can be a micron-size particle. In some embodiments, the catalytic material comprises about 1 wt% to about 7 wt% platinum group metal. In some embodiments, the plurality of the composite nanoparticles and the plurality of non-catalytic spacer nanoparticles are present in the catalytic material at a ratio of about 1 : 1 to about 1 : 50.

In some embodiments of the catalytic material, the catalytic material comprises a plurality of composite nanoparticles comprising a support nanoparticle comprising alumina and lanthana, and a catalytic nanoparticle comprising platinum, palladium, or a mixture thereof); a plurality of non-catalytic spacer nanoparticles; and a porous carrier that bridges together the plurality of composite nanoparticles and the plurality of spacer nanoparticles. The catalytic material can be a micron-size particle. In some embodiments, the catalytic material comprises about 1 wt% to about 7 wt% platinum group metal. In some embodiments, the plurality of the composite nanoparticles and the plurality of non-catalytic spacer nanoparticles are present in the catalytic material at a ratio of about 1 : 1 to about 1 : 50.

In some embodiments of the catalytic material, the catalytic material comprises a plurality of composite nanoparticles comprising a support nanoparticle comprising alumina and a catalytic nanoparticle comprising platinum, palladium, or a mixture thereof); a plurality of non-catalytic spacer nanoparticles; and a porous carrier comprising alumina that bridges together the plurality of composite nanoparticles and the plurality of spacer nanoparticles. The catalytic material can be a micron- size particle. In some embodiments, the catalytic material comprises about 1 wt% to about 7 wt% platinum group metal . In some embodiments, the plurality of the composite nanoparticles and the plurality of non-catalytic spacer nanoparticles are present in the catalytic material at a ratio of about 1 : 1 to about 1 : 50.

In some embodiments of the catalytic material, the catalytic material comprises a plurality of composite nanoparticles comprising a support nanoparticle comprising alumina and lanthana, and a catalytic nanoparticle comprising platinum, palladium, or a mixture thereof); a plurality of non-catalytic spacer nanoparticles; and a porous carrier comprising alumina and lanthana that bridges together the plurality of composite nanoparticles and the plurality of spacer nanoparticles. The catalytic material can be a micron-size particle. In some embodiments, the catalytic material comprises about 1 wt% to about 7 wt% platinum group metal. In some embodiments, the plurality of the composite nanoparticles and the plurality of non- catalytic spacer nanoparticles are present in the catalytic material at a ratio of about 1 : 1 to about 1 : 50.

In some embodiments of the catalytic material, the catalytic material comprises a plurality of composite nanoparticles comprising a support nanoparticle and a catalytic nanoparticle comprising at least one platinum group metal (such as platinum, palladium, rhodium, or an alloy thereof, for example a mixture of platinum and palladium); a plurality of non-catalytic spacer nanoparticles

comprising a metal oxide; and a porous carrier that bridges together the plurality of composite nanoparticles and the plurality of spacer nanoparticles. The catalytic material can be a micron-size particle. In some embodiments, the catalytic material comprises about 1 wt% to about 7 wt% platinum group metal. In some

embodiments, the plurality of the composite nanoparticles and the plurality of non- catalytic spacer nanoparticles are present in the catalytic material at a ratio of about 1 : 1 to about 1 : 50.

In some embodiments of the catalytic material, the catalytic material comprises a plurality of composite nanoparticles comprising a support nanoparticle comprising alumina and a catalytic nanoparticle comprising platinum, palladium, or a mixture thereof; a plurality of non-catalytic spacer nanoparticles comprising alumina; and a porous carrier that bridges together the plurality of composite nanoparticles and the plurality of spacer nanoparticles. The catalytic material can be a micron-size particle. In some embodiments, the catalytic material comprises about 1 wt% to about 7 wt% platinum group metal. In some embodiments, the plurality of the composite nanoparticles and the plurality of non-catalytic spacer nanoparticles are present in the catalytic material at a ratio of about 1 : 1 to about 1 : 50.

In some embodiments of the catalytic material, the catalytic material comprises a plurality of composite nanoparticles comprising a support nanoparticle comprising alumina and lanthana, and a catalytic nanoparticle comprising platinum, palladium, or a mixture thereof; a plurality of non-catalytic spacer nanoparticles comprising alumina and lanthana; and a porous carrier that bridges together the plurality of composite nanoparticles and the plurality of spacer nanoparticles. The catalytic material can be a micron-size particle. In some embodiments, the catalytic material comprises about 1 wt% to about 7 wt% platinum group metal. In some

embodiments, the plurality of the composite nanoparticles and the plurality of non- catalytic spacer nanoparticles are present in the catalytic material at a ratio of about 1 : 1 to about 1 : 50.

In some embodiments of the catalytic material, the catalytic material comprises a plurality of composite nanoparticles comprising a support nanoparticle comprising alumina and a catalytic nanoparticle comprising platinum, palladium, or a mixture thereof); a plurality of non-catalytic spacer nanoparticles comprising alumina; and a porous carrier comprising alumina that bridges together the plurality of composite nanoparticles and the plurality of spacer nanoparticles. The catalytic material can be a micron-size particle. In some embodiments, the catalytic material comprises about 1 wt% to about 7 wt% platinum group metal . In some embodiments, the plurality of the composite nanoparticles and the plurality of non-catalytic spacer nanoparticles are present in the catalytic material at a ratio of about 1 : 1 to about 1 : 50.

In some embodiments of the catalytic material, the catalytic material comprises a plurality of composite nanoparticles comprising a support nanoparticle comprising alumina and lanthana, and a catalytic nanoparticle comprising platinum, palladium, or a mixture thereof); a plurality of non-catalytic spacer nanoparticles comprising alumina and lanthana; and a porous carrier comprising alumina and lanthana that bridges together the plurality of composite nanoparticles and the plurality of spacer nanoparticles. The catalytic material can be a micron-size particle. In some embodiments, the catalytic material comprises about 1 wt% to about 7 wt% platinum group metal. In some embodiments, the plurality of the composite nanoparticles and the plurality of non-catalytic spacer nanoparticles are present in the catalytic material at a ratio of about 1 : 1 to about 1 : 50.

In another aspect, a catalytic material comprises a plurality of composite

nanoparticles comprising a support nanoparticle and a catalytic nanoparticle; a plurality of non-catalytic spacer nanoparticles; and a carrier that bridges together the composite nanoparticles and the spacer nanoparticles, wherein the carrier comprises a combustible component and a non-combustible component. In some embodiments, the catalytic material comprises about 1 wt% to about 7 wt% platinum group metal. In some embodiments, the plurality of the composite nanoparticles and the plurality of non-catalytic spacer nanoparticles are present in the catalytic material at a ratio of about 1 : 1 to about 1 : 50.

In some embodiments, the catalytic material comprises a plurality of composite nanoparticles comprising a support nanoparticle and a catalytic nanoparticle; a plurality of non-catalytic spacer nanoparticles; and a carrier that bridges together the composite nanoparticles and the spacer nanoparticles, wherein the carrier comprises a combustible component comprising polymerized resorcinol and a non-combustible component comprising a metal oxide. In some embodiments, the catalytic material comprises about 1 wt% to about 7 wt% platinum group metal . In some embodiments, the plurality of the composite nanoparticles and the plurality of non-catalytic spacer nanoparticles are present in the catalytic material at a ratio of about 1 : 1 to about 1 : 50.

In some embodiments, the catalytic material comprises a plurality of composite nanoparticles comprising a support nanoparticle and a catalytic nanoparticle comprising a platinum group metal (such as platinum, palladium, rhodium, or a mixture thereof, for example a mixture of platinum and palladium); a plurality of non-catalytic spacer nanoparticles; and a carrier that bridges together the composite nanoparticles and the spacer nanoparticles, wherein the carrier comprises a combustible component comprising polymerized resorcinol and a non-combustible component comprising a metal oxide. In some embodiments, the catalytic material comprises about 1 wt% to about 7 wt% platinum group metal. In some embodiments, the plurality of the composite nanoparticles and the plurality of non-catalytic spacer nanoparticles are present in the catalytic material at a ratio of about 1 : 1 to about 1 : 50. In some embodiments, the catalytic material comprises a plurality of composite nanoparticles comprising a support nanoparticle comprising a metal oxide and a catalytic nanoparticle comprising a platinum group metal (such as platinum, palladium, rhodium, or a mixture thereof, for example a mixture of platinum and palladium); a plurality of non-catalytic spacer nanoparticles comprising a metal oxide; and a carrier that bridges together the composite nanoparticles and the spacer nanoparticles, wherein the carrier comprises a combustible component comprising polymerized resorcinol and a non-combustible component comprising a metal oxide. In some embodiments, the catalytic material comprises about 1 wt% to about 7 wt% platinum group metal . In some embodiments, the plurality of the composite nanoparticles and the plurality of non-catalytic spacer nanoparticles are present in the catalytic material at a ratio of about 1 : 1 to about 1 : 50.

In some embodiments, the catalytic material comprises a plurality of composite nanoparticles comprising a support nanoparticle comprising alumina and a catalytic nanoparticle comprising platinum, palladium, or a mixture thereof; a plurality of non-catalytic spacer nanoparticles comprising a metal oxide; and a carrier that bridges together the composite nanoparticles and the spacer nanoparticles, wherein the carrier comprises a combustible component comprising polymerized resorcinol and a non-combustible component comprising a metal oxide. In some

embodiments, the catalytic material comprises about 1 wt% to about 7 wt% platinum group metal. In some embodiments, the plurality of the composite nanoparticles and the plurality of non-catalytic spacer nanoparticles are present in the catalytic material at a ratio of about 1 : 1 to about 1 : 50.

In some embodiments, the catalytic material comprises a plurality of composite nanoparticles comprising a support nanoparticle comprising alumina and lanthana, and a catalytic nanoparticle comprising platinum, palladium, or a mixture thereof; a plurality of non-catalytic spacer nanoparticles comprising a metal oxide; and a carrier that bridges together the composite nanoparticles and the spacer

nanoparticles, wherein the carrier comprises a combustible component comprising polymerized resorcinol and a non-combustible component comprising a metal oxide. In some embodiments, the catalytic material comprises about 1 wt% to about 7 wt% platinum group metal. In some embodiments, the plurality of the composite nanoparticles and the plurality of non-catalytic spacer nanoparticles are present in the catalytic material at a ratio of about 1 : 1 to about 1 : 50.

In some embodiments, the catalytic material comprises a plurality of composite nanoparticles comprising a support nanoparticle comprising alumina and a catalytic nanoparticle comprising platinum, palladium, or a mixture thereof; a plurality of non-catalytic spacer nanoparticles comprising a metal oxide; and a carrier that bridges together the composite nanoparticles and the spacer nanoparticles, wherein the carrier comprises a combustible component comprising polymerized resorcinol and a non-combustible component comprising alumina. In some embodiments, the catalytic material comprises about 1 wt% to about 7 wt% platinum group metal. In some embodiments, the plurality of the composite nanoparticles and the plurality of non-catalytic spacer nanoparticles are present in the catalytic material at a ratio of about 1 : 1 to about 1 : 50.

In some embodiments, the catalytic material comprises a plurality of composite nanoparticles comprising a support nanoparticle comprising alumina and lanthana, and a catalytic nanoparticle comprising platinum, palladium, or a mixture thereof; a plurality of non-catalytic spacer nanoparticles comprising a metal oxide; and a carrier that bridges together the composite nanoparticles and the spacer

nanoparticles, wherein the carrier comprises a combustible component comprising polymerized resorcinol and a non-combustible component comprising alumina and lanthana. In some embodiments, the catalytic material comprises about 1 wt% to about 7 wt% platinum group metal. In some embodiments, the plurality of the composite nanoparticles and the plurality of non-catalytic spacer nanoparticles are present in the catalytic material at a ratio of about 1 : 1 to about 1 : 50.

Production of Catalytic Materials

The catalytic material can be produced by mixing a plurality of composite

nanoparticles and a plurality of spacer nanoparticles with a liquid comprising a carrier precursor, wherein the composite nanoparticles comprise a support nanoparticle and a catalytic nanoparticle; and solidifying the carrier precursor to form a solidified carrier that bridges together the plurality of composite

nanoparticles and the plurality of spacer nanoparticles. The spacer nanoparticles can consist essentially of a refractory material. In some embodiments, the spacer nanoparticles are substantially free from a catalytic metal (such as a platinum group metal) . In some embodiments, the spacer nanoparticles are non-catalytic. The solidified carrier can include a combustible component and a non-combustible component. In some embodiments, a portion of the solidified carrier, such as the combustible component, is removed to form a porous catalytic material. Optionally, the catalytic material can be processed into micron-sized particles, such as by milling the catalytic material.

Described below is the production of catalytic materials using a porous aluminum oxide carrier formed using a composite carrier comprising a combustible organic gel component and an aluminum oxide component, followed by drying and calcination. However, one skilled in the art would understand any manner of porous carrier originating from soluble precursors may be used to produce the catalytic materials described herein.

For typical catalytic materials, the spacer nanoparticles (such as metal oxide (e.g., one or more of aluminum oxide, lanthanum oxide, or a mixture thereof)

nanoparticles or boehmite nanoparticles) are initially dispersed in ethanol or other organic solvent. In some embodiments, at least 90 vol%, at least 95 vol%, at least 99 vol%, or at least 99.9 vol% ethanol is used. Dispersants, antifoaming agents, and/or surfactants are preferably added to the ethanol, either before or after suspending the spacer nanoparticles in the ethanol . A suitable surfactant includes DisperBYK ^® -145 from BYK-Chemie GmbH LLC, Wesel, which can be added in a range of about 2 wt% to about 12 wt%, with about 6.7 wt% being a typical value. A suitable dispersant can include dodecylamine, which can be added in a range of about 0.25 wt% to about 3 wt%, with about 1 wt% being a typical value. A suitable antifoaming agent includes Shamrock antifoam, which can be added in a range of about 0.01 wt% to about 0.1 wt%, with about 0.05 wt% being a typical value. Preferably, both DisperBYK ^® -145 and Shamrock antifoam are used at about 6.7 wt% and about 0.05 wt%, respectively. The quantity of spacer nanoparticles particles in the dispersion may be in the range of about 5 wt% to about 20 wt% (such as about 10 wt% to about 15 wt%). The mixture of ethanol, spacer nanoparticles, and surfactants, antifoaming agents, and/or dispersants can be sonicated to uniformly disperse the spacer nanoparticles in a nanoparticle dispersion. Optionally, the dispersion is centrifuged to remove aggregates from the dispersion.

Composite nanoparticles are also dispersed in a liquid, such as an aqueous liquid. The aqueous liquid can include a dispersant and/or an antifoaming agent. A suitable dispersant for the aqueous composite nanoparticle suspension includes Jeffsperse ^® x3503 (Huntsman, The Woodlands, Texas, USA), which can be included at an amount of about 1 wt% to about 7 wt%, with a preferred amount being about 3 wt%. A suitable dispersant can include dodecylamine, which can be added in a range of about 0.25 wt% to about 3 wt%, with about 1 wt% being a typical value. The quantity of composite nanoparticles particles in the dispersion may be in the range of about 1 wt% to about 25 wt% (such as about 5 wt% to about 20 wt%, or about 6 wt% to about 8 wt%). The mixture of aqueous liquid (which can include dispersants, antifoaming agents, and/or surfactants) and composite nanoparticles can be sonicated to uniformly disperse the composite nanoparticles in a

nanoparticle dispersion. Optionally, the dispersion is centrifuged to remove aggregates from the dispersion.

The dispersion comprising the spacer nanoparticles and the dispersion comprising the composite nanoparticles are mixed, and optionally sonicated in further homogenize the suspension . The proportions or amounts of the spacer nanoparticle dispersion and the composite nanoparticle dispersion are selected to obtain a desired ratio of spacer nanoparticles to composite nanoparticles, or a desired amount of catalytic metal (such as platinum group metal) in the final catalytic material . Selecting the amount of the spacer nanoparticle dispersion and the composite nanoparticle dispersion based on the desired amount of catalytic metal in the produce catalytic material can also include taking into account the amount of porous carrier that will be included in the final product.

Separately from the spacer nanoparticle and composite nanoparticle suspension, a gel activation solution containing crosslinking agents is prepared. The crosslinking agents can be, for example, formaldehyde and propylene oxide. The formaldehyde is preferably in an aqueous solution (for example, a 37 wt% formaldehyde solution) . The aqueous formaldehyde solution may contain one or more stabilizers, such as about 5 wt% to about 15 wt% methanol. The aqueous formaldehyde solution can be added in a range of about 25% to about 50% of the final weight of the gel activation solution, with the remainder being propylene oxide. Preferably, the gel activation solution comprises about 37.5 wt% of the aqueous formaldehyde solution (which itself comprises 37 wt% formaldehyde) and about 62.5 wt% propylene oxide, resulting in a final formaldehyde concentration of about 14 wt% of the final gel activation solution .

Separately from the nanoparticle suspension and gel activation solution, a gel precursor solution is produced by dissolving a non-combustible carrier precursor with a combustible carrier precursor in an organic solution (such as ethanol). The non-combustible carrier precursor is a salt that contains ions that will result in the non-combustible portion of the carrier. For example, in some embodiments the non-combustible portion of the carrier comprises aluminum oxide; accordingly, the non-combustible carrier precursor in the gel precursor solution can be, for example aluminum nitrate. In some embodiments, the non-combustible portion of the carrier includes or further includes lanthanum oxide, and the non-combustible carrier precursor of the gel precursor solution can include lanthanum chloride. Other precursors (e.g., metal oxide precursors) can be used, such as aluminum chloride, lanthanum acetate, cerium nitrate, zirconium oxynitrate, yttrium nitrate, zirconium acetate, zirconium nitrate, or neodymium nitrate. The combustible carrier precursor includes an organic polymerizing resin, such as resorcinol. Resorcinol can be included in the gel precursor solution at a range of about 10 wt% to about 30 wt%, with about 20 wt% being a typical value. Aluminum nitrate can be added at a range of about 5 wt% to about 25 wt%, with about 18 wt% being a typical value.

The nanoparticle suspension is mixed with the gel activation solution, and the combined mixture is mixed with the gel precursor solution. The final mixture will begin to polymerize into a carrier that bridges together the spacer nanoparticles and the composite nanoparticles. The carrier comprises a combustible component, an organic gel, and a non-combustible component, the metal oxide. The resulting carrier may then be dried (for example, at about 30°C to about 95°C, preferably about 50°C to about 60°C, at atmospheric pressure or at reduced pressure such as from about 1 pascal to about 90,000 pascal, for about one day to about 5 days, or for about 2 days to about 3 days) . After drying, the resulting carrier with

nanoparticles may then be calcined (at elevated temperatures, such as from 400°C to about 700°C, preferably about 500°C to about 600°C, more preferably at about 540°C to about 560°C, still more preferably at about 550°C to about 560°C, or at about 550°C; at atmospheric pressure or at reduced pressure, for example, from about 1 pascal to about 90,000 pascal, in ambient atmosphere or under an inert atmosphere such as nitrogen or argon) . When the composite carrier is calcined under ambient atmosphere or other oxygenated conditions, organic material, such as polymerized resorcinol, formaldehyde, or propylene oxide, is burned off, resulting in a non-combustible porous carrier that bridges together the spacer nanoparticles and the composite nanoparticles. If the composite carrier is calcined under an inert atmosphere, such as argon or nitrogen, the organic materials may become substantially porous amorphous carbon interspersed with the porous aluminum oxide embedded with composite nanoparticles. The resulting porous carrier can be processed, such as by grinding or milling, into a micro-sized powder. A stabilizing metal oxide (such as lanthanum oxide, yttrium oxide, or neodymium oxide) can be included in the non-combustible portion of the carrier by including a stabilizing metal oxide precursor (i.e., a stabilizing metal salt, such as lanthanum acetate, lanthanum chloride, yttrium nitrate, or neodymium nitrate) during the manufacturing process. The stabilizing metal oxide enhances the stability of the carrier during operation, wh ich can occur at elevated temperatu res . The stabilizing metal oxide precu rsor can be converted into the stabilizing metal oxide by calcining the material u nder atmospheric or oxidizing conditions . The stabilizing metal oxide precursor can be dissolved in an aqueous solution, and can be included in the gel precursor solution prior to polymerization, or can be added to the catalytic material either before or after drying the catalytic material . For example, in some

embodiments, the nanoparticle suspension, the gel activation solution, and the gel precursor solution are combined to form the catalyst material (which includes a combustible polymerized gel component and a non-combustible component) . An aqueous solution contain ing a stabilizing metal oxide precursor can then be added to the catalyst material, which is then dried and calcined . In some embodiments, the catalyst material is dried and the stabil izing metal oxide precursor aqueous sol ution is added to the dried catalyst material (for example, to the point of incipient wetness) . The catalyst material wetted with the stabilizing metal oxide precursor aqueous sol ution can then be dried and calcined . In some embodiments, the catalyst material may be dried and calcined (and optionally processed into a micron-sized powder) before the stabilizing metal oxide precu rsor solution is added to the catalyst material (for example, to the point of incipient wetness), which can then be again dried and calcined .

In one embodiment, a porous catalytic material is produced by mixing plu rality of composite nanoparticles and a plurality of non-catalytic spacer nanoparticles with a liquid comprising a carrier precursor, wherein the composite nanoparticles comprise a support nanoparticle and a catalytic nanoparticle; solidifying the carrier precursor to form a solidified carrier that bridges together the pl urality of composite na noparticles and the plurality of spacer nanoparticles; and removing a portion of the sol idified carrier to form the porous catalytic material . In some embodiments, the method fu rther includes stabilizing the carrier with a stabilizing metal oxide (such as lanthanum oxide, yttrium oxide, or neodymium oxide) . Th is can be done, for example, by applying a stabilizing metal oxide precu rsor (e .g ., a salt) to the solidified catalytic material, drying the catalytic material, and calcining the solidified material . Alternatively, the stabil izing metal oxide precursor can be added to any one or more of the liquids prior to solidifying the catalytic material .

In some embodiments, a porous catalytic material is produced by mixing plurality of composite nanoparticles and a plurality of non-catalytic spacer nanoparticles with a liquid comprising a carrier precu rsor, wherein the composite nanoparticles comprise a support nanoparticle and a catalytic nanoparticle; solidifying the carrier precursor to form a combustible component of the solidified carrier and a non- combustible component of the solidified carrier; and the removing the combustible component of the solidified carrier to form the porous catalytic material . The combustible component of the sol idified carrier can be removed by calcin ing the solidified carrier. In some embodiments, the method further includes stabil izing the carrier with a stabilizing metal oxide (such as lanthanum oxide, yttrium oxide, or neodymium oxide) . Th is can be done, for example, by applying a stabilizing metal oxide precu rsor (e .g ., a salt) to the solidified catalytic material, drying the catalytic material, and calcining the sol idified material . Alternatively, the stabilizing metal oxide precu rsor can be added to any one or more of the liqu ids prior to solidifying the catalytic material .

In some embodiments, a porous catalytic material is produced by mixing a plurality of composite nanoparticles and a plurality of non-catalytic spacer nanoparticles prior to mixing the pl urality of composite nanoparticles and the plurality of non- catalytic spacer nanoparticles with a liqu id contain ing the carrier precursor, wherein the composite nanoparticles comprise a support nanoparticle and a catalytic nanoparticle; sol idifying the carrier precursor to form a combustible component of the solidified carrier and a non-combustible component of the solidified carrier; and the removing the combustible component of the solidified carrier to form the porous catalytic material . The combustible component of the solidified carrier can be removed by calcin ing the solidified carrier. In some embodiments, the method further includes stabilizing the carrier with a stabilizing metal oxide (such as lanthanum oxide, yttrium oxide, or neodymium oxide) . This can be done, for example, by applying a stabilizing metal oxide precursor (e.g ., a salt) to the solidified catalytic material, drying the catalytic material, and calcining the solidified material . Alternatively, the stabil izing metal oxide precursor can be added to any one or more of the liquids prior to solidifying the catalytic material .

In some embodiments, a porous catalytic material is produced by mixing plurality of composite nanoparticles and a plurality of non-catalytic spacer nanoparticles with a liquid comprising a carrier precursor, wherein the composite nanoparticles comprise a support nanoparticle and a catalytic nanoparticle; solidifying the carrier precursor to form a combustible component and a non-combustible component comprising aluminum oxide; and the removing the combustible component of the sol idified carrier to form the porous catalytic material . The combustible component of the solidified carrier can be removed by calcin ing the solidified carrier. In some embodiments, the method further includes stabilizing the carrier with a stabilizing metal oxide (such as lanthanum oxide, yttrium oxide, or neodymium oxide) . This can be done, for example, by applying a stabilizing metal oxide precursor (e .g ., a salt) to the solidified catalytic material, drying the catalytic material, and calcining the sol idified material . Alternatively, the stabilizing metal oxide precursor can be added to any one or more of the l iquids prior to solidifying the catalytic material . In some embodiments, a porous catalytic material is produced by mixing a plu rality of composite nanoparticles and a plurality of non-catalytic spacer nanoparticles prior to mixing the plu ral ity of composite nanoparticles and the pl urality of non- catalytic spacer nanoparticles with a liquid containing the carrier precursor, wherein the composite nanoparticles comprise a support nanoparticle and a catalytic nanoparticle; solidifying the carrier precursor to form a combustible component and a non-combustible component comprising aluminum oxide; and the removing the combustible component of the solidified carrier to form the porous catalytic material . The combustible component of the solidified carrier can be removed by calcining the solidified carrier. In some embodiments, the method further includes stabilizing the carrier with a stabilizing metal oxide (such as lanthanum oxide, yttrium oxide, or neodymium oxide) . Th is can be done, for example, by applying a stabilizing metal oxide precursor (e .g ., a salt) to the solidified catalytic material, drying the catalytic material, and calcining the solidified material. Alternatively, the stabilizing metal oxide precursor can be added to any one or more of the liquids prior to solidifying the catalytic material.

In some embodiments, a porous catalytic material is produced by mixing plurality of composite nanoparticles and a plurality of non-catalytic spacer nanoparticles with a liquid comprising a carrier precursor comprising resorcinol and a crosslinking agent (such as formaldehyde and/or propylene oxide), wherein the composite nanoparticles comprise a support nanoparticle and a catalytic nanoparticle;

solidifying the carrier precursor to form a combustible component and a non- combustible component comprising aluminum oxide; and the removing the combustible component of the solidified carrier to form the porous catalytic material. The combustible component of the solidified carrier can be removed by calcining the solidified carrier. In some embodiments, the method further includes stabilizing the carrier with a stabilizing metal oxide (such as lanthanum oxide, yttrium oxide, or neodymium oxide). This can be done, for example, by applying a stabilizing metal oxide precursor (e.g., a salt) to the solidified catalytic material, drying the catalytic material, and calcining the solidified material. Alternatively, the stabilizing metal oxide precursor can be added to any one or more of the liquids prior to solidifying the catalytic material.

In some embodiments, a porous catalytic material is produced by mixing a plurality of composite nanoparticles and a plurality of non-catalytic spacer nanoparticles prior to mixing the plurality of composite nanoparticles and the plurality of non- catalytic spacer nanoparticles with a liquid containing the carrier precursor comprising resorcinol and a crosslinking agent (such as formaldehyde and/or propylene oxide), wherein the composite nanoparticles comprise a support nanoparticle and a catalytic nanoparticle; solidifying the carrier precursor to form a combustible component and a non-combustible component comprising aluminum oxide; and the removing the combustible component of the solidified carrier to form the porous catalytic material . The combustible component of the solidified carrier can be removed by calcining the solidified carrier. In some embodiments, the method fu rther includes stabilizing the carrier with a stabil izing metal oxide (such as lanthan um oxide, yttrium oxide, or neodymium oxide) . This can be done, for example, by applying a stabilizing metal oxide precursor (e.g . , a salt) to the solidified catalytic material, drying the catalytic material, and calcining the solidified material . Alternatively, the stabil izing metal oxide precursor can be added to any one or more of the liquids prior to solidifying the catalytic material .

In some embodiments, a porous catalytic material is produced by mixing plurality of composite nanoparticles and a plurality of non-catalytic spacer nanoparticles comprising a metal oxide with a liquid comprising a carrier precursor comprising resorcinol and a crossl inking agent (such as formaldehyde and/or propylene oxide), wherein the composite nanoparticles comprise a support nanoparticle comprising a metal oxide and a catalytic nanoparticle comprising a platinum group metal (such as rhodium, platinum, palladium, or a mixtu re thereof) ; solidifying the carrier precursor to form a combustible component and a non-combustible component comprising aluminum oxide; and the removing the combustible component of the sol idified carrier to form the porous catalytic material . The combustible component of the solidified carrier can be removed by calcin ing the solidified carrier. In some embodiments, the method further includes stabilizing the carrier with a stabilizing metal oxide (such as lanthanum oxide, yttrium oxide, or neodymiu m oxide) . This can be done, for example, by applying a stabilizing metal oxide precursor (e .g ., a salt) to the solidified catalytic material, drying the catalytic material, and calcining the sol idified material . Alternatively, the stabilizing metal oxide precursor can be added to any one or more of the l iquids prior to solidifying the catalytic material . In some embodiments, a porous catalytic material is produced by mixing a plurality of composite nanoparticles and a plurality of non-catalytic spacer nanoparticles comprising a metal oxide prior to mixing the plurality of composite nanoparticles and the plurality of non-catalytic spacer nanoparticles with a liquid containing the carrier precursor comprising resorcinol and a crosslinking agent (such as

formaldehyde and/or propylene oxide), wherein the composite nanoparticles comprise a support nanoparticle comprising a metal oxide and a catalytic nanoparticle comprising a platinum group metal (such as rhodium, platinum, palladium, or a mixture thereof); solidifying the carrier precursor to form a combustible component and a non-combustible component comprising aluminum oxide; and the removing the combustible component of the solidified carrier to form the porous catalytic material. The combustible component of the solidified carrier can be removed by calcining the solidified carrier. In some embodiments, the method further includes stabilizing the carrier with a stabilizing metal oxide (such as lanthanum oxide, yttrium oxide, or neodymium oxide). This can be done, for example, by applying a stabilizing metal oxide precursor (e.g., a salt) to the solidified catalytic material, drying the catalytic material, and calcining the solidified material . Alternatively, the stabilizing metal oxide precursor can be added to any one or more of the liquids prior to solidifying the catalytic material.

In some embodiments, a porous catalytic material is produced by mixing plurality of composite nanoparticles and a plurality of non-catalytic spacer nanoparticles comprising a aluminum oxide with a liquid comprising a carrier precursor

comprising resorcinol and a crosslinking agent (such as formaldehyde and/or propylene oxide), wherein the composite nanoparticles comprise a support nanoparticle comprising aluminum oxide and a catalytic nanoparticle comprising a platinum group metal (such as rhodium, platinum, palladium, or a mixture thereof); solidifying the carrier precursor to form a combustible component and a non- combustible component comprising aluminum oxide; and the removing the combustible component of the solidified carrier to form the porous catalytic material. The combustible component of the solidified carrier can be removed by calcining the solidified carrier. In some embodiments, the method further includes stabilizing the carrier with a stabilizing metal oxide (such as lanthanum oxide, yttrium oxide, or neodymium oxide). This can be done, for example, by applying a stabilizing metal oxide precursor (e.g., a salt) to the solidified catalytic material, drying the catalytic material, and calcining the solidified material. Alternatively, the stabilizing metal oxide precursor can be added to any one or more of the liquids prior to solidifying the catalytic material. In some embodiments, a porous catalytic material is produced by mixing a plurality of composite nanoparticles and a plurality of non-catalytic spacer nanoparticles comprising a aluminum oxide prior to mixing the plurality of composite

nanoparticles and the plurality of non-catalytic spacer nanoparticles with a liquid containing the carrier precursor comprising resorcinol and a crosslinking agent (such as formaldehyde and/or propylene oxide), wherein the composite

nanoparticles comprise a support nanoparticle comprising aluminum oxide and a catalytic nanoparticle comprising a platinum group metal (such as rhodium, platinum, palladium, or a mixture thereof); solidifying the carrier precursor to form a combustible component and a non-combustible component comprising aluminum oxide; and the removing the combustible component of the solidified carrier to form the porous catalytic material. The combustible component of the solidified carrier can be removed by calcining the solidified carrier. In some embodiments, the method further includes stabilizing the carrier with a stabilizing metal oxide (such as lanthanum oxide, yttrium oxide, or neodymium oxide). This can be done, for example, by applying a stabilizing metal oxide precursor (e.g., a salt) to the solidified catalytic material, drying the catalytic material, and calcining the solidified material . Alternatively, the stabilizing metal oxide precursor can be added to any one or more of the liquids prior to solidifying the catalytic material.

In some embodiments, a porous catalytic material is produced by mixing plurality of composite nanoparticles and a plurality of non-catalytic spacer nanoparticles comprising aluminum oxide and lanthanum oxide with a liquid comprising a carrier precursor comprising resorcinol and a crosslinking agent (such as formaldehyde and/or propylene oxide), wherein the composite nanoparticles comprise a support nanoparticle comprising aluminum oxide and a catalytic nanoparticle comprising a platinum group metal (such as rhodium, platinum, palladium, or a mixture thereof); solidifying the carrier precursor to form a combustible component and a non- combustible component comprising aluminum oxide; and the removing the combustible component of the solidified carrier to form the porous catalytic material. The combustible component of the solidified carrier can be removed by calcining the solidified carrier. In some embodiments, the method further includes stabilizing the carrier with a stabilizing metal oxide (such as lanthanum oxide, yttrium oxide, or neodymium oxide). This can be done, for example, by applying a stabilizing metal oxide precursor (e.g., a salt) to the solidified catalytic material, drying the catalytic material, and calcining the solidified material. Alternatively, the stabilizing metal oxide precursor can be added to any one or more of the liquids prior to solidifying the catalytic material.

In some embodiments, a porous catalytic material is produced by mixing a plurality of composite nanoparticles and a plurality of non-catalytic spacer nanoparticles comprising aluminum oxide and lanthanum oxide prior to mixing the plurality of composite nanoparticles and the plurality of non-catalytic spacer nanoparticles with a liquid containing the carrier precursor comprising resorcinol and a crosslinking agent (such as formaldehyde and/or propylene oxide), wherein the composite nanoparticles comprise a support nanoparticle comprising aluminum oxide and a catalytic nanoparticle comprising a platinum group metal (such as rhodium, platinum, palladium, or a mixture thereof); solidifying the carrier precursor to form a combustible component and a non-combustible component comprising aluminum oxide; and the removing the combustible component of the solidified carrier to form the porous catalytic material. The combustible component of the solidified carrier can be removed by calcining the solidified carrier. In some embodiments, the method further includes stabilizing the carrier with a stabilizing metal oxide (such as lanthanum oxide, yttrium oxide, or neodymium oxide). This can be done, for example, by applying a stabilizing metal oxide precursor (e.g., a salt) to the solidified catalytic material, drying the catalytic material, and calcining the solidified material . Alternatively, the stabilizing metal oxide precursor can be added to any one or more of the liquids prior to solidifying the catalytic material .

In some embodiments, a porous catalytic material is produced by mixing plurality of composite nanoparticles and a plurality of non-catalytic spacer nanoparticles comprising aluminum oxide and lanthanum oxide with a liquid comprising a carrier precursor comprising resorcinol and a crosslinking agent (such as formaldehyde and/or propylene oxide), wherein the composite nanoparticles comprise a support nanoparticle comprising aluminum oxide and lanthanum oxide, and a catalytic nanoparticle comprising a platinum group metal (such as rhodium, platinum, palladium, or a mixture thereof); solidifying the carrier precursor to form a combustible component and a non-combustible component comprising aluminum oxide; and the removing the combustible component of the solidified carrier to form the porous catalytic material. The combustible component of the solidified carrier can be removed by calcining the solidified carrier. In some embodiments, the method further includes stabilizing the carrier with a stabilizing metal oxide (such as lanthanum oxide, yttrium oxide, or neodymium oxide). This can be done, for example, by applying a stabilizing metal oxide precursor (e.g., a salt) to the solidified catalytic material, drying the catalytic material, and calcining the solidified material . Alternatively, the stabilizing metal oxide precursor can be added to any one or more of the liquids prior to solidifying the catalytic material.

In some embodiments, a porous catalytic material is produced by mixing a plurality of composite nanoparticles and a plurality of non-catalytic spacer nanoparticles comprising aluminum oxide and lanthanum oxide prior to mixing the plurality of composite nanoparticles and the plurality of non-catalytic spacer nanoparticles with a liquid containing the carrier precursor comprising resorcinol and a crosslinking agent (such as formaldehyde and/or propylene oxide), wherein the composite nanoparticles comprise a support nanoparticle comprising aluminum oxide and lanthanum oxide, and a catalytic nanoparticle comprising a platinum group metal (such as rhodium, platinum, palladium, or a mixture thereof); solidifying the carrier precursor to form a combustible component and a non-combustible component comprising aluminum oxide; and the removing the combustible component of the solidified carrier to form the porous catalytic material. The combustible component of the solidified carrier can be removed by calcining the solidified carrier. In some embodiments, the method further includes stabilizing the carrier with a stabilizing metal oxide (such as lanthanum oxide, yttrium oxide, or neodymium oxide). This can be done, for example, by applying a stabilizing metal oxide precursor (e.g., a salt) to the sol idified catalytic material, drying the catalytic material, and calcining the sol idified material . Alternatively, the stabilizing metal oxide precursor can be added to any one or more of the l iquids prior to solidifying the catalytic material . In another aspect, a cata lytic material is produced by mixing pl urality of composite nanoparticles and a plurality of non-catalytic spacer nanoparticles with a l iquid comprising a carrier precursor, wherein the composite nanoparticles comprise a su pport nanoparticle and a catalytic nanoparticle; and solidifying the carrier precursor to form a solidified carrier that bridges together the plu rality of composite nanoparticles and the plurality of spacer nanoparticles. In some embodiments, the method further includes stabilizing the carrier with a stabil izing metal oxide (such as lanthan um oxide, yttrium oxide, or neodymium oxide) . This can be done, for example, by applying a stabilizing metal oxide precursor (e .g ., a salt) to the solidified catalytic material, drying the catalytic material, and calcining the solidified material . Alternatively, the stabil izing metal oxide precursor can be added to any one or more of the liquids prior to solidifying the catalytic material .

In some embodiments, a catalytic material is produced by mixing plurality of composite nanoparticles and a plurality of non-catalytic spacer nanoparticles with a liquid comprising a carrier precursor, wherein the composite nanoparticles comprise a support nanoparticle and a catalytic nanoparticle; and solidifying the ca rrier precursor to form a combustible component of the solidified carrier and a non- combustible component of the solidified carrier. In some embodiments, the method further includes stabilizing the carrier with a stabilizing metal oxide (such as lanthanu m oxide, yttrium oxide, or neodymium oxide) . This can be done, for example, by applying a stabilizing metal oxide precursor (e .g ., a salt) to the solidified catalytic material, drying the catalytic material, and calcining the solidified material . Alternatively, the stabilizing metal oxide precu rsor can be added to any one or more of the liquids prior to solidifying the catalytic material .

In some embodiments, a catalytic material is produced by mixing a plurality of composite nanoparticles and a plurality of non-catalytic spacer nanoparticles prior to mixing the plu rality of composite nanoparticles and the plu rality of non -catalytic spacer nanoparticles with a liquid containing the carrier precursor, wherein the composite nanoparticles comprise a support nanoparticle and a catalytic

nanoparticle; and solidifying the carrier precursor to form a combustible component of the solidified carrier and a non-combustible component of the solidified carrier. In some embodiments, the method further includes stabilizing the carrier with a stabilizing metal oxide (such as lanthanum oxide, yttrium oxide, or neodymium oxide). This can be done, for example, by applying a stabilizing metal oxide precursor (e.g., a salt) to the solidified catalytic material, drying the catalytic material, and calcining the solidified material. Alternatively, the stabilizing metal oxide precursor can be added to any one or more of the liquids prior to solidifying the catalytic material.

In some embodiments, a catalytic material is produced by mixing plurality of composite nanoparticles and a plurality of non-catalytic spacer nanoparticles with a liquid comprising a carrier precursor, wherein the composite nanoparticles comprise a support nanoparticle and a catalytic nanoparticle; and solidifying the carrier precursor to form a combustible component and a non-combustible component comprising aluminum oxide. In some embodiments, the method further includes stabilizing the carrier with a stabilizing metal oxide (such as lanthanum oxide, yttrium oxide, or neodymium oxide). This can be done, for example, by applying a stabilizing metal oxide precursor (e.g., a salt) to the solidified catalytic material, drying the catalytic material, and calcining the solidified material. Alternatively, the stabilizing metal oxide precursor can be added to any one or more of the liquids prior to solidifying the catalytic material.

In some embodiments, a catalytic material is produced by mixing a plurality of composite nanoparticles and a plurality of non-catalytic spacer nanoparticles prior to mixing the plurality of composite nanoparticles and the plurality of non-catalytic spacer nanoparticles with a liquid containing the carrier precursor, wherein the composite nanoparticles comprise a support nanoparticle and a catalytic

nanoparticle; and solidifying the carrier precursor to form a combustible component and a non-combustible component comprising aluminum oxide. In some embodiments, the method further includes stabilizing the carrier with a stabilizing metal oxide (such as lanthanum oxide, yttrium oxide, or neodymium oxide). This can be done, for example, by applying a stabilizing metal oxide precursor (e.g., a salt) to the solidified catalytic material, drying the catalytic material, and calcining the solidified material. Alternatively, the stabilizing metal oxide precursor can be added to any one or more of the liquids prior to solidifying the catalytic material. In some embodiments, a catalytic material is produced by mixing plurality of composite nanoparticles and a plurality of non-catalytic spacer nanoparticles with a liquid comprising a carrier precursor comprising resorcinol and a crosslinking agent (such as formaldehyde and/or propylene oxide), wherein the composite

nanoparticles comprise a support nanoparticle and a catalytic nanoparticle; and solidifying the carrier precursor to form a combustible component and a non- combustible component comprising aluminum oxide. In some embodiments, the method further includes stabilizing the carrier with a stabilizing metal oxide (such as lanthanum oxide, yttrium oxide, or neodymium oxide). This can be done, for example, by applying a stabilizing metal oxide precursor (e.g., a salt) to the solidified catalytic material, drying the catalytic material, and calcining the solidified material . Alternatively, the stabilizing metal oxide precursor can be added to any one or more of the liquids prior to solidifying the catalytic material.

In some embodiments, a catalytic material is produced by mixing a plurality of composite nanoparticles and a plurality of non-catalytic spacer nanoparticles prior to mixing the plurality of composite nanoparticles and the plurality of non-catalytic spacer nanoparticles with a liquid containing the carrier precursor comprising resorcinol and a crosslinking agent (such as formaldehyde and/or propylene oxide), wherein the composite nanoparticles comprise a support nanoparticle and a catalytic nanoparticle; and solidifying the carrier precursor to form a combustible component and a non-combustible component comprising aluminum oxide. In some embodiments, the method further includes stabilizing the carrier with a stabilizing metal oxide (such as lanthanum oxide, yttrium oxide, or neodymium oxide). This can be done, for example, by applying a stabilizing metal oxide precursor (e.g., a salt) to the solidified catalytic material, drying the catalytic material, and calcining the solidified material. Alternatively, the stabilizing metal oxide precursor can be added to any one or more of the liquids prior to solidifying the catalytic material. In some embodiments, a catalytic material is produced by mixing plurality of composite nanoparticles and a plurality of non-catalytic spacer nanoparticles comprising a metal oxide with a liquid comprising a carrier precursor comprising resorcinol and a crosslinking agent (such as formaldehyde and/or propylene oxide), wherein the composite nanoparticles comprise a support nanoparticle comprising a metal oxide and a catalytic nanoparticle comprising a platinum group metal (such as rhodium, platinum, palladium, or a mixture thereof); and solidifying the carrier precursor to form a combustible component and a non-combustible component comprising aluminum oxide. The combustible component of the solidified carrier can be removed by calcining the solidified carrier. In some embodiments, the method further includes stabilizing the carrier with a stabilizing metal oxide (such as lanthanum oxide, yttrium oxide, or neodymium oxide). This can be done, for example, by applying a stabilizing metal oxide precursor (e.g., a salt) to the solidified catalytic material, drying the catalytic material, and calcining the solidified material . Alternatively, the stabilizing metal oxide precursor can be added to any one or more of the liquids prior to solidifying the catalytic material.

In some embodiments, a catalytic material is produced by mixing a plurality of composite nanoparticles and a plurality of non-catalytic spacer nanoparticles comprising a metal oxide prior to mixing the plurality of composite nanoparticles and the plurality of non-catalytic spacer nanoparticles with a liquid containing the carrier precursor comprising resorcinol and a crosslinking agent (such as

formaldehyde and/or propylene oxide), wherein the composite nanoparticles comprise a support nanoparticle comprising a metal oxide and a catalytic

nanoparticle comprising a platinum group metal (such as rhodium, platinum, palladium, or a mixture thereof); and solidifying the carrier precursor to form a combustible component and a non-combustible component comprising aluminum oxide. In some embodiments, the method further includes stabilizing the carrier with a stabilizing metal oxide (such as lanthanum oxide, yttrium oxide, or neodymium oxide). This can be done, for example, by applying a stabilizing metal oxide precursor (e.g., a salt) to the solidified catalytic material, drying the catalytic material, and calcining the solidified material. Alternatively, the stabilizing metal oxide precursor can be added to any one or more of the liquids prior to solidifying the catalytic material.

In some embodiments, a catalytic material is produced by mixing plurality of composite nanoparticles and a plurality of non-catalytic spacer nanoparticles comprising a aluminum oxide with a liquid comprising a carrier precursor

comprising resorcinol and a crosslinking agent (such as formaldehyde and/or propylene oxide), wherein the composite nanoparticles comprise a support nanoparticle comprising aluminum oxide and a catalytic nanoparticle comprising a platinum group metal (such as rhodium, platinum, palladium, or a mixture thereof); and solidifying the carrier precursor to form a combustible component and a non- combustible component comprising aluminum oxide. In some embodiments, the method further includes stabilizing the carrier with a stabilizing metal oxide (such as lanthanum oxide, yttrium oxide, or neodymium oxide). This can be done, for example, by applying a stabilizing metal oxide precursor (e.g., a salt) to the solidified catalytic material, drying the catalytic material, and calcining the solidified material . Alternatively, the stabilizing metal oxide precursor can be added to any one or more of the liquids prior to solidifying the catalytic material.

In some embodiments, a catalytic material is produced by mixing a plurality of composite nanoparticles and a plurality of non-catalytic spacer nanoparticles comprising a aluminum oxide prior to mixing the plurality of composite

nanoparticles and the plurality of non-catalytic spacer nanoparticles with a liquid containing the carrier precursor comprising resorcinol and a crosslinking agent (such as formaldehyde and/or propylene oxide), wherein the composite

nanoparticles comprise a support nanoparticle comprising aluminum oxide and a catalytic nanoparticle comprising a platinum group metal (such as rhodium, platinum, palladium, or a mixture thereof); and solidifying the carrier precursor to form a combustible component and a non-combustible component comprising aluminum oxide. In some embodiments, the method further includes stabilizing the carrier with a stabilizing metal oxide (such as lanthanum oxide, yttrium oxide, or neodymium oxide). This can be done, for example, by applying a stabilizing metal oxide precursor (e.g., a salt) to the solidified catalytic material, drying the catalytic material, and calcining the solidified material. Alternatively, the stabilizing metal oxide precursor can be added to any one or more of the liquids prior to solidifying the catalytic material.

In some embodiments, a catalytic material is produced by mixing plurality of composite nanoparticles and a plurality of non-catalytic spacer nanoparticles comprising aluminum oxide and lanthanum oxide with a liquid comprising a carrier precursor comprising resorcinol and a crosslinking agent (such as formaldehyde and/or propylene oxide), wherein the composite nanoparticles comprise a support nanoparticle comprising aluminum oxide and a catalytic nanoparticle comprising a platinum group metal (such as rhodium, platinum, palladium, or a mixture thereof); and solidifying the carrier precursor to form a combustible component and a non- combustible component comprising aluminum oxide. In some embodiments, the method further includes stabilizing the carrier with a stabilizing metal oxide (such as lanthanum oxide, yttrium oxide, or neodymium oxide). This can be done, for example, by applying a stabilizing metal oxide precursor (e.g., a salt) to the solidified catalytic material, drying the catalytic material, and calcining the solidified material. Alternatively, the stabilizing metal oxide precursor can be added to any one or more of the liquids prior to solidifying the catalytic material.

In some embodiments, a catalytic material is produced by mixing a plurality of composite nanoparticles and a plurality of non-catalytic spacer nanoparticles comprising aluminum oxide and lanthanum oxide prior to mixing the plurality of composite nanoparticles and the plurality of non-catalytic spacer nanoparticles with a liquid containing the carrier precursor comprising resorcinol and a crosslinking agent (such as formaldehyde and/or propylene oxide), wherein the composite nanoparticles comprise a support nanoparticle comprising aluminum oxide and a catalytic nanoparticle comprising a platinum group metal (such as rhodium, platinum, palladium, or a mixture thereof); and solidifying the carrier precursor to form a combustible component and a non-combustible component comprising aluminum oxide. In some embodiments, the method further includes stabilizing the carrier with a stabilizing metal oxide (such as lanthanum oxide, yttrium oxide, or neodymium oxide). This can be done, for example, by applying a stabilizing metal oxide precursor (e.g., a salt) to the solidified catalytic material, drying the catalytic material, and calcining the solidified material. Alternatively, the stabilizing metal oxide precursor can be added to any one or more of the liquids prior to solidifying the catalytic material.

In some embodiments, a catalytic material is produced by mixing plurality of composite nanoparticles and a plurality of non-catalytic spacer nanoparticles comprising aluminum oxide and lanthanum oxide with a liquid comprising a carrier precursor comprising resorcinol and a crosslinking agent (such as formaldehyde and/or propylene oxide), wherein the composite nanoparticles comprise a support nanoparticle comprising aluminum oxide and lanthanum oxide, and a catalytic nanoparticle comprising a platinum group metal (such as rhodium, platinum, palladium, or a mixture thereof); and solidifying the carrier precursor to form a combustible component and a non-combustible component comprising aluminum oxide. The combustible component of the solidified carrier can be removed by calcining the solidified carrier. In some embodiments, the method further includes stabilizing the carrier with a stabilizing metal oxide (such as lanthanum oxide, yttrium oxide, or neodymium oxide). This can be done, for example, by applying a stabilizing metal oxide precursor (e.g., a salt) to the solidified catalytic material, drying the catalytic material, and calcining the solidified material. Alternatively, the stabilizing metal oxide precursor can be added to any one or more of the liquids prior to solidifying the catalytic material.

In some embodiments, a catalytic material is produced by mixing a plurality of composite nanoparticles and a plurality of non-catalytic spacer nanoparticles comprising aluminum oxide and lanthanum oxide prior to mixing the plurality of composite nanoparticles and the plurality of non-catalytic spacer nanoparticles with a liquid containing the carrier precursor comprising resorcinol and a crosslinking agent (such as formaldehyde and/or propylene oxide), wherein the composite nanoparticles comprise a support nanoparticle comprising aluminum oxide and lanthanum oxide, and a catalytic nanoparticle comprising a platinum group metal (such as rhodium, platinum, palladium, or a mixture thereof); and solidifying the carrier precursor to form a combustible component and a non-combustible component comprising aluminum oxide. In some embodiments, the method further includes stabilizing the carrier with a stabilizing metal oxide (such as lanthanum oxide, yttrium oxide, or neodymium oxide) . This can be done, for example, by applying a stabilizing metal oxide precursor (e.g., a salt) to the solidified catalytic material, drying the catalytic material, and calcining the solidified material.

Alternatively, the stabilizing metal oxide precursor can be added to any one or more of the liquids prior to solidifying the catalytic material.

Washcoat Compositions and Coated Substrates Using Micron-Sized Catalytic Materials

The catalytic materials described herein can be included in one or more washcoat compositions, which can be used to provide one or more layers on a substrate used for catalysis, such as a catalytic converter substrate. The catalytic materials allow for reduced amounts of platinum group metals, reduced catalyst aging, and offer better performance when compared to previous washcoat compositions and coated catalytic converter substrates.

Washcoats are prepared by suspending micron-sized particles of catalyst material in an aqueous solution, adjusting the pH to between about 2 and about 7, to between about 3 and about 5, or to about 4. The viscosity of the washcoat composition can be adjusted, if necessary, using cellulose, cornstarch, or other thickeners.

Generally, the viscosity of the washcoat composition is adjusted to a value between about 300 cP to about 1200 cP, although variations can be made depending on the intended use. In some embodiments, the catalytic washcoat are applied to a substrate to produce a coated substrate. Micron-sized filler particles, such as micron-sized alumina particles, can also be included in the washcoat composition, if desired. Boehmite can also be include in the washcoat composition.

The initial substrate is preferably a catalytic converter substrate that demonstrates good thermal stability, including resistance to thermal shock, and to which the described washcoats can be affixed in a stable manner. Suitable substrates include, but are not limited to, substrates formed from cordierite or other ceramic materials, and substrates formed from metal. The substrates may include a honeycomb structure, which provides numerous channels and results in a high surface area. The high surface area of the coated substrate with its applied washcoats in the catalytic converter provides for effective treatment of the exhaust gas flowing through the catalytic converter.

The washcoat is applied to the substrate by coating the substrate with the aqueous solution comprising micron-sized catalyst material particles, blowing excess washcoat off of the substrate (and optionally collecting and recycling the excess washcoat blown off of the substrate), drying the substrate, and calcining the substrate.

Drying of the washcoats coated onto the substrate can be performed at room temperature or elevated temperature (for example, from about 30°C to about 95°C, preferably about 60°C to about 70°C), at atmospheric pressure or at reduced pressure (for example, from about 1 pascal to about 90,000 pascal, or from about 7.5 mTorr to about 675 Torr), in ambient atmosphere or under an inert atmosphere (such as nitrogen or argon), and with or without passing a stream of gas over the substrate (for example, dry air, dry nitrogen gas or dry argon gas). In some embodiments, the drying process is a hot-drying process. A hot drying process includes any way to remove the solvent at a temperature greater than room temperature, but at a temperature below a standard calcining temperature. In some embodiments, the drying process may be a flash drying process, involving the rapid evaporation of moisture from the substrate via a sudden reduction in pressure or by placing the substrate in an updraft of warm air. It is contemplated that other drying processes may also be used.

After drying the washcoat onto the substrate, the washcoat may then be calcined onto the substrate. Calcining takes place at elevated temperatures, such as from 400°C to about 700°C, preferably about 500°C to about 600°C, more preferably at about 540°C to about 560°C or at about 550°C. Calcining can take place at atmospheric pressure or at reduced pressure (for example, from about 1 pascal to about 90,000 pascal, or about 7.5 mTorr to about 675 Torr), in ambient

atmosphere or under an inert atmosphere (such as nitrogen or argon), and with or without passing a stream of gas over the substrate (for example, dry air, dry nitrogen gas, or dry argon gas). This process yields a substrate coated with a washcoat layer comprising micron-sized particles of catalyst material.

FIG. 1 illustrates a catalytic converter in accordance with some embodiments.

Micron-sized catalytic material is included in a washcoat composition, which is coated onto a substrate to form a coated substrate. The coated substrate 114 is enclosed within an insulating material 112, which in turn is enclosed within a metallic container 110 (of, for example, stainless steel). A heat shield 108 and a gas sensor (for example, an oxygen sensor) 106 are depicted. The catalytic converter may be affixed to the exhaust system of the vehicle through flanges 104 and 118. The exhaust gas, which includes the raw emissions of hydrocarbons, carbon monoxide, and nitrogen oxides, enters the catalytic converter at 102. As the raw emissions pass through the catalytic converter, they react with the catalytically active material on the coated substrate, resulting in tailpipe emissions of water, carbon dioxide, and nitrogen exiting at 120. FIG. 1A is a magnified view of a section of the coated substrate 114, which shows the honeycomb structure of the coated substrate. The coated substrates, which are discussed in further detail below, may be incorporated into a catalytic converter for use in a vehicle emissions control system.

In some embodiments, there is provided a coated substrate comprising a substrate, and a washcoat layer comprising micron-sized catalytic particles, the micron-sized catalytic particles comprising a pl urality of composite nanoparticles comprising a support nanoparticle and a catalytic nanoparticle; a pl urality of non-catalytic spacer nanoparticles; and a porous carrier that bridges together the plural ity of composite nanoparticles and the pl urality of spacer nanoparticles.

In some embodiments, there is provided a coated su bstrate comprising a substrate, and a washcoat layer comprising micron-sized catalytic particles, the micron-sized catalytic particles comprising a plu ral ity of composite nanoparticles comprising a support nanoparticle and a catalytic nanoparticle comprising at least one platin um group metal (such as platinu m, palladium, rhodium, or an alloy thereof, for example a mixture of platinum and palladium) ; a plurality of non-catalytic spacer nanoparticles; and a porous carrier that bridges together the plural ity of composite nanoparticles and the plurality of spacer nanoparticles.

In some embodiments, there is provided a coated su bstrate comprising a substrate, and a washcoat layer comprising micron-sized catalytic particles, the micron-sized catalytic particles comprising a plu rality of composite nanoparticles comprising a support nanoparticle comprising alumina and a catalytic nanoparticle comprising platinum, pal ladium, or a mixture thereof) ; a plurality of non-catalytic spacer nanoparticles; and a porous carrier that bridges together the plural ity of composite nanoparticles and the plu rality of spacer nanoparticles .

In some embodiments, there is provided a coated substrate comprising a substrate, and a washcoat layer comprising micron-sized catalytic particles, the micron-sized catalytic particles comprising a plu rality of composite nanoparticles comprising a support nanoparticle comprising alumina and lanthana, and a catalytic nanopa rticle comprising platinum, palladium, or a mixture thereof) ; a pl urality of non-catalytic spacer nanoparticles; and a porous carrier that bridges together the pl urality of composite nanoparticles and the plu rality of spacer nanoparticles .

In some embodiments, there is provided a coated substrate comprising a substrate, and a washcoat layer comprising micron-sized catalytic particles, the micron-sized catalytic particles comprising a plu rality of composite nanoparticles comprising a support nanoparticle comprising alu mina and a catalytic nanoparticle comprising platinum, palladium, or a mixture thereof); a plurality of non-catalytic spacer nanoparticles; and a porous carrier comprising alumina that bridges together the plurality of composite nanoparticles and the plurality of spacer nanoparticles.

In some embodiments, there is provided a coated substrate comprising a substrate, and a washcoat layer comprising micron-sized catalytic particles, the micron-sized catalytic particles comprising a plurality of composite nanoparticles comprising a support nanoparticle comprising alumina and lanthana, and a catalytic nanoparticle comprising platinum, palladium, or a mixture thereof); a plurality of non-catalytic spacer nanoparticles; and a porous carrier comprising alumina and lanthana that bridges together the plurality of composite nanoparticles and the plurality of spacer nanoparticles.

In some embodiments, there is provided a coated substrate comprising a substrate, and a washcoat layer comprising micron-sized catalytic particles, the micron-sized catalytic particles comprising a plurality of composite nanoparticles comprising a support nanoparticle and a catalytic nanoparticle comprising at least one platinum group metal (such as platinum, palladium, rhodium, or an alloy thereof, for example a mixture of platinum and palladium); a plurality of non-catalytic spacer nanoparticles comprising a metal oxide; and a porous carrier that bridges together the plurality of composite nanoparticles and the plurality of spacer nanoparticles. In some embodiments, there is provided a coated substrate comprising a substrate, and a washcoat layer comprising micron-sized catalytic particles, the micron-sized catalytic particles comprising a plurality of composite nanoparticles comprising a support nanoparticle comprising alumina and a catalytic nanoparticle comprising platinum, palladium, or a mixture thereof; a plurality of non-catalytic spacer nanoparticles comprising alumina; and a porous carrier that bridges together the plurality of composite nanoparticles and the plurality of spacer nanoparticles.

In some embodiments, there is provided a coated substrate comprising a substrate, and a washcoat layer comprising micron-sized catalytic particles, the micron-sized catalytic particles comprising a plurality of composite nanoparticles comprising a support nanoparticle comprising alumina and lanthana, and a catalytic nanoparticle comprising platinum, palladium, or a mixture thereof; a plurality of non-catalytic spacer nanoparticles comprising alumina and lanthana; and a porous carrier that bridges together the plurality of composite nanoparticles and the plurality of spacer nanoparticles.

In some embodiments, there is provided a coated substrate comprising a substrate, and a washcoat layer comprising micron-sized catalytic particles, the micron-sized catalytic particles comprising a plurality of composite nanoparticles comprising a support nanoparticle comprising alumina and a catalytic nanoparticle comprising platinum, palladium, or a mixture thereof); a plurality of non-catalytic spacer nanoparticles comprising alumina; and a porous carrier comprising alumina that bridges together the plurality of composite nanoparticles and the plurality of spacer nanoparticles.

In some embodiments, there is provided a coated substrate comprising a substrate, and a washcoat layer comprising micron-sized catalytic particles, the micron-sized catalytic particles comprising a plurality of composite nanoparticles comprising a support nanoparticle comprising alumina and lanthana, and a catalytic nanoparticle comprising platinum, palladium, or a mixture thereof); a plurality of non-catalytic spacer nanoparticles comprising alumina and lanthana; and a porous carrier comprising alumina and lanthana that bridges together the plurality of composite nanoparticles and the plurality of spacer nanoparticles.

Exhaust Systems, Vehicles, and Emissions Performance

In some embodiments of the invention, a coated substrate as disclosed herein is housed within a catalytic converter in a position configured to receive exhaust gas from an internal combustion engine, such as in an exhaust system of an internal combustion engine. The coated substrate is placed into a housing, which can in turn be placed into an exhaust system (also referred to as an exhaust treatment system) of an internal combustion engine. The exhaust system of the internal combustion engine receives exhaust gases from the engine, typically into an exhaust manifold, and delivers the exhaust gases to an exhaust treatment system. The catalytic converter forms part of the exhaust system and is often referred to as the diesel oxidation catalyst (DOC). The exhaust system can also include a diesel particulate filter (DPF) and/or a selective catalytic reduction unit (SCR unit) and/or a lean NOx trap (LNT); typical arrangements, in the sequence that exhaust gases are received from the engine, are DOC-DPF and DOC-DPF-SCR. The exhaust system can also include other components, such as oxygen sensors, HEGO (heated exhaust gas oxygen) sensors, UEGO (universal exhaust gas oxygen) sensors, sensors for other gases, and temperature sensors. The exhaust system can also include a controller such as an engine control unit (ECU), a microprocessor, or an engine management computer, which can adjust various parameters in the vehicle (fuel flow rate, fuel/air ratio, fuel injection, engine timing, valve timing, etc.) in order to optimize the components of the exhaust gases that reach the exhaust treatment system, so as to manage the emissions released into the environment. Comparison of Catalyst Performance Described Herein to Commercially Available and Other Non-Commercially Available Catalysts

The catalytic material described herein may be used for a variety of applications, for example, as a component in various catalytic washcoat formulations to be coated on a substrate, which may be used in a catalytic converter, which may then be used in the exhaust treatment system of an automobile. Commercially available catalytic converters are generally produced using wet-chemistry methods to place platinum group metals, such as palladium or platinum, within a washcoat formulation. Catalytic converters produced using wet-chemistry methods can be compared to catalytic converters using catalytic particles, such as NNm particles, as described in U.S. Patent No. 8,679,433, or NNiM particles, as described in U.S. Patent Pub. No. 2015/0140317.

To compare the catalytic efficiency of wet-chemistry catalysts, NNm particles, NNiM particles, and the micron-sized catalytic material described herein, the catalysts may be separately employed in catalytic converters, aged (for example, by using the catalytic converters with an actual automobile or artificially, such as by heating the catalytic converter to 800 °C for 16 hours), and a carbon monoxide "light-off" temperature may be measured for each catalytic converter at various platinum group metal loadings. A carbon monoxide "light-off" temperature is generally considered the operational temperature of a catalytic converter, and the

temperature at which 50% of carbon monoxide is catalyzed. A lower light-off temperature for a given PGM load, or a lower PGM load for a given light-off temperature, is therefore indicative of a more efficient catalyst.

In some embodiments, a catalytic converter made with the micron-sized catalytic material described herein, loaded with 1.8 g/l of PGM or less, displays a carbon monoxide light-off temperature at least 10 degrees C lower than a catalytic converter made with wet chemistry methods and having the same or similar PGM loading. In some embodiments, a catalytic converter made with c the micron-sized catalytic material described herein, loaded with 1.8 g/l of PGM or less, displays a carbon monoxide light-off temperature at least 20 degrees C lower than a catalytic converter made with wet chemistry methods and having the same or similar PGM loading. In some embodiments, a catalytic converter made with the micron-sized catalytic material described herein, loaded with 1.8 g/l of PGM or less, displays a carbon monoxide light-off temperature at least 30 degrees C lower than a catalytic converter made with wet chemistry methods and having the same or similar PGM loading. In some embodiments, a catalytic converter made with the micron-sized catalytic material described herein, loaded with 1.8 g/l of PGM or less, displays a carbon monoxide light-off temperature at least 40 degrees C lower than a catalytic converter made with wet chemistry methods and having the same or similar PGM loading. In some embodiments, the micron-sized catalytic material described herein, loaded with 1.8 g/l of PGM or less, displays a carbon monoxide light-off temperature at least 50 degrees C lower than a catalytic converter made with wet chemistry methods and having the same or similar PGM loading. In some embodiments, a catalytic converter made with the micron-sized catalytic material described herein, loaded with 1.5 g/l of PGM or less, displays a carbon monoxide light-off temperature at least 10 degrees C lower than a catalytic converter made with wet chemistry methods and having the same or similar PGM loading . In some embodiments, a catalytic converter made with the micron-sized catalytic material described herein, loaded with 1.5 g/l of PGM or less, displays a carbon monoxide light-off temperature at least 20 degrees C lower than a catalytic converter made with wet chemistry methods and having the same or similar PGM loading . In some embodiments, a catalytic converter made with the micron-sized catalytic material described herein, loaded with 1.5 g/l of PGM or less, displays a carbon monoxide light-off temperature at least 30 degrees C lower than a catalytic converter made with wet chemistry methods and having the same or similar PGM loading . In some embodiments, a catalytic converter made with the micron-sized catalytic material described herein, loaded with 1.5 g/l of PGM or less, displays a carbon monoxide light-off temperature at least 40 degrees C lower than a catalytic converter made with wet chemistry methods and having the same or similar PGM loading . In some embodiments, a catalytic converter made with the micron-sized catalytic material described herein demonstrates any of the foregoing performance standards after about 50,000 km, about 50,000 miles, about 75,000 km, about 75,000 miles, about 100,000 km, about 100,000 miles, about 125,000 km, about 125,000 miles, about 150,000 km, or about 150,000 miles of operation .

In some embodiments, a catalytic converter made with the micron-sized catalytic material described herein demonstrates a carbon monoxide light-off temperature within +/- 3 degrees C of the carbon monoxide light-off temperature of a catalytic converter made with wet chemistry methods, while the catalytic converter made with the micron-sized catalytic material described herein employs about 30 wt% less, about 40 wt% less, about 50 wt% less, about 60 wt% less, about 70 wt% less, or about 80 wt% less PGM than the catalytic converter made with wet chemistry methods. In some embodiments, the catalytic converter made with the micron-sized catalytic material described herein demonstrates this performance after about 50,000 km, about 50,000 miles, about 75,000 km, about 75,000 miles, about 100,000 km, about 100,000 miles, about 125,000 km, about 125,000 miles, about 150,000 km, or about 150,000 miles of operation . In some embodiments, a catalytic converter made with the micron-sized catalytic material described herein demonstrates a carbon monoxide light-off temperature within +/- 2 degrees C of the carbon monoxide light-off temperature of a catalytic converter made with wet chemistry methods, while the catalytic converter made with the micron-sized catalytic material described herein employs about 30 wt% less, about 40 wt% less, about 50 wt% less, about 60 wt% less, about 70 wt% less, or about 80 wt% less catalyst than the catalytic converter made with wet chemistry methods. In some embodiments, the catalytic converter made with the micron-sized catalytic material described herein demonstrates this performance after about 50,000 km, about 50,000 miles, about 75,000 km, about 75,000 miles, about 100,000 km, about 100,000 miles, about 125,000 km, about 125,000 miles, about 150,000 km, or about 150,000 miles of operation.

In some embodiments, for the above-described comparisons, both the catalytic converter made with composite nanoparticles embedded within a porous carrier, and the commercially available catalytic converter prepared using wet chemistry methods, are aged (by the same amount) prior to testing. In some embodiments, both the catalytic converter made with composite nanoparticles embedded within a porous carrier, and the commercially available catalytic converter prepared using wet chemistry methods, are aged to about (or up to about) 50,000 kilometers, about (or up to about) 50,000 miles, about (or up to about) 75,000 kilometers, about (or up to about) 75,000 miles, about (or up to about) 100,000 kilometers, about (or up to about) 100,000 miles, about (or up to about) 125,000 kilometers, about (or up to about) 125,000 miles, about (or up to about) 150,000 kilometers, or about (or up to about) 150,000 miles. In some embodiments, for the above- described comparisons, both the catalytic converter made with composite nanoparticles embedded within a porous carrier, and the commercially available catalytic converter prepared using wet chemistry methods, are artificially aged (by the same amount) prior to testing. In some embodiments, they are artificially aged by heating to about 400°C, about 500 °C, about 600°C, about 700° , about 800°C, about 900°C, about 1000°C, about 1100°C, or about 1200°C for about (or up to about) 4 hours, about (or up to about) 6 hours, about (or up to about) 8 hours, about (or up to about) 10 hours, about (or up to about) 12 hours, about (or up to about) 14 hours, about (or up to about) 16 hours, about (or up to about) 18 hours, about (or up to about) 20 hours, about (or up to about) 22 hours, or about (or up to about) 24 hours. In some embodiments, they are artificially aged by heating to about 800°C for about 16 hours.

Exemplary embodiments

Embodiment 1. A catalytic material comprising :

a plurality of composite nanoparticles comprising a support nanoparticle and a catalytic nanoparticle;

a plurality of non-catalytic spacer nanoparticles; and

a porous carrier that bridges together the plurality of composite

nanoparticles and the plurality of spacer nanoparticles.

Embodiment 2. The catalytic material of embodiment 1, wherein the catalytic material is a micron-size particle.

Embodiment 3. The catalytic material of embodiment 1 or embodiment 2, wherein the catalytic nanoparticle comprises at least one platinum group metal.

Embodiment 4. The catalytic material of embodiment 3, wherein the catalytic nanoparticle comprises rhodium.

Embodiment 5. The catalytic material of embodiment 3, wherein the catalytic nanoparticle comprises platinum or palladium.

Embodiment 6. The catalytic material of embodiment 3, wherein the catalytic nanoparticle comprises platinum and palladium.

Embodiment 7. The catalytic material of embodiment 6, wherein the catalytic nanoparticle comprises platinum and palladium in a weight ratio of about 1 :2 platinum : palladium to about 25 : 1 platinum : palladium.

Embodiment 8. The catalytic material of embodiment 6, wherein the catalytic nanoparticle comprises platinum and palladium in a weight ratio of about 2 : 1 platinum : palladium to about 10 : 1 platinum : palladium. Embodiment 9. The catalytic material of embodiment 6, wherein the catalytic nanoparticle comprises platinum and palladium in a weight ratio of 2: 1 platinum : palladium.

Embodiment 10. The catalytic material of embodiment 6, wherein the catalytic nanoparticle comprises platinum and palladium in a weight ratio of 10 : 1 platinum : palladium.

Embodiment 11. The catalytic material of embodiment 5, wherein the catalytic nanoparticle comprises platinum and is substantially free of palladium.

Embodiment 12. The catalytic material of embodiment 5, wherein the catalytic nanoparticle comprises palladium and is substantially free of platinum.

Embodiment 13. The catalytic material of any one of embodiments 1-12, wherein the composite nanoparticles comprise about 10 wt% to 70 wt% catalytic metal. Embodiment 14. The catalytic material of any one of embodiments 1-13, wherein the composite nanoparticles comprise about 30 wt% to 50 wt% platinum group metal.

Embodiment 15. The catalytic material of any one of embodiments 1-14, wherein the catalytic nanoparticle has a diameter between 1 nm and 10 nm.

Embodiment 16. The catalytic material of any one of embodiments 1-15, wherein the support nanoparticle has a diameter of 10 nm to 20 nm.

Embodiment 17. The catalytic material of any one of embodiments 1-16, wherein the support nanoparticle comprises a metal oxide.

Embodiment 18. The catalytic material of embodiment 17, wherein the support nanoparticle comprises aluminum oxide, cerium oxide, zirconium oxide, lanthanum oxide, yttrium oxide, silica, neodymium oxide, or a combination thereof.

Embodiment 19. The catalytic material of embodiment 17, wherein the support nanoparticle comprises aluminum oxide and the catalytic material comprises platinum or palladium.

Embodiment 20. The catalytic material of embodiment 17, wherein the support nanoparticle comprises cerium oxide and the catalytic particle comprises rhodium. Embodiment 21. The catalytic material of any one of embodiments 1-20, wherein the spacer nanoparticles comprise a metal oxide.

Embodiment 22. The catalytic material of embodiment 21, wherein the spacer nanoparticles comprises aluminum oxide, cerium oxide, zirconium oxide, lanthanum oxide, yttrium oxide, silica, neodymium oxide, or a combination thereof.

Embodiment 23. The catalytic material of any one of embodiments 1-22, wherein the support nanoparticle and the spacer nanoparticles are the same material.

Embodiment 24. The catalytic material of any one of embodiments 1-23, wherein the spacer nanoparticles and the porous carrier comprise the same material .

Embodiment 25. The catalytic material of any one of embodiments 1-24, wherein the porous carrier comprises a metal oxide.

Embodiment 26. The catalytic material of embodiment 25, wherein the porous carrier comprises aluminum oxide, cerium oxide, zirconium oxide, lanthanum oxide, yttrium oxide, silica, neodymium oxide, or a combination thereof.

Embodiment 27. The catalytic material of embodiment 25, wherein the porous carrier comprises aluminum oxide, the spacer nanoparticles comprise aluminum oxide, the support nanoparticle comprises aluminum oxide, and the catalytic material comprises platinum or palladium.

Embodiment 28. The catalytic material of embodiment 27, wherein the porous carrier further comprises lanthanum oxide.

Embodiment 29. The catalytic material of embodiment 25, wherein the porous carrier comprises cerium oxide, the spacer nanoparticles comprise cerium oxide, the support nanoparticle comprises cerium oxide, and the catalytic particle comprises rhodium.

Embodiment 30. The catalytic material of any one of embodiments 1-29, wherein the catalytic material has a BET surface area of about 200 m2/g or more.

Embodiment 31. The catalytic material of any one of embodiments 1-30, wherein the catalytic material has an average pore diameter of about 1 nm to about 200 nm. Embodiment 32. The catalytic material of any one of embodiments 1-31, wherein the plurality of the composite nanoparticles and the plurality of non-catalytic spacer nanoparticles are present in the catalytic material at a ratio of about 1 : 1 to about 1 : 50.

Embodiment 33. The catalytic material of any one of embodiments 1-32, wherein the catalytic material comprises about 1 wt% to about 7 wt% platinum group metal.

Embodiment 34. A method of producing a porous catalytic material comprising : mixing a plurality of composite nanoparticles and a plurality of non-catalytic spacer nanoparticles with a liquid comprising a carrier precursor, wherein the composite nanoparticles comprise a support nanoparticle and a catalytic nanoparticle;

solidifying the carrier precursor to form a solidified carrier that bridges together the plurality of composite nanoparticles and the plurality of spacer nanoparticles; and removing a portion of the solidified carrier to form the porous catalytic material . Embodiment 35. The method of embodiment 34, wherein the carrier precursor is solidified to form a combustible component of the solidified carrier and a non- combustible component of the solidified carrier, and the combustible component of the solidified carrier is removed to form the porous catalytic material.

Embodiment 36. The method according to embodiment 35, wherein the

combustible component of the solidified carrier is removed by calcining the solidified carrier.

Embodiment 37. The method of any one of embodiments 34-36, further

comprising :

mixing a plurality of composite nanoparticles and a plurality of non-catalytic spacer nanoparticles prior to mixing the plurality of composite nanoparticles and the plurality of non-catalytic spacer nanoparticles with the liquid containing the carrier precursor.

Embodiment 38. The method of any one of embodiments 34-37, further comprising stabilizing the carrier with a stabilizing metal oxide. Embodiment 39. The method of embodiment 38, wherein the stabilizing metal oxide is lanthanum oxide.

Embodiment 40. The method of embodiment 38 or 39, wherein the carrier is stabilized by applying a stabilizing metal oxide precursor solution to the catalytic material, drying the catalytic material, and calcining the catalytic material .

Embodiment 41. The method of any one of embodiments 34-40, wherein the solidified carrier comprises aluminum oxide, cerium oxide, zirconium oxide, lanthanum oxide, yttrium oxide, silica, neodymium oxide, or a combination thereof.

Embodiment 42. The method of any one of embodiments 34-41, wherein the solidified carrier comprises aluminum oxide and lanthanum oxide.

Embodiment 43. The method of any one of embodiments 34-42, wherein the carrier precursor comprises a combustible component comprising resorcinol.

Embodiment 44. The method of embodiment 43, the carrier precursor further comprising a crosslinking agent.

Embodiment 45. The method of embodiment 43 or 44, wherein the carrier precursor comprises formaldehyde and propylene oxide.

Embodiment 46. The method of any one of embodiments 34-45, wherein the carrier precursor is solidified by polymerization.

Embodiment 47. The method of any one of embodiments 34-46, wherein the catalytic nanoparticle comprises at least one platinum group metal .

Embodiment 48. The method of any one of embodiments 34-47, wherein the catalytic nanoparticle comprises rhodium.

Embodiment 49. The method of any one of embodiments 34-48, wherein the catalytic nanoparticle comprises platinum or palladium.

Embodiment 50. The method of any one of embodiments 34-49, wherein the catalytic nanoparticle comprises platinum and palladium.

Embodiment 51. The methodof embodiment 49 or 50, wherein the catalytic nanoparticle comprises platinum and palladium in a weight ratio of about 1 :2 platinum : palladium to about 25 : 1 platinum : palladium. Embodiment 52. The method of any one of embodiments 49-51, wherein the catalytic nanoparticle comprises platinum and palladium in a weight ratio of about 2: 1 platinum : palladium to about 10 : 1 platinum : palladium.

Embodiment 53. The method of embodiment 49, wherein the catalytic nanoparticle comprises platinum and is substantially free of palladium.

Embodiment 54. The method of embodiment 49, wherein the catalytic nanoparticle comprises palladium and is substantially free of platinum.

Embodiment 55. The method of any one of embodiments 34-54, wherein the composite nanoparticles comprise about 10 wt% to 70 wt% platinum group metal. Embodiment 56. The method of any one of embodiments 34-55, wherein the composite nanoparticles comprise about 30 wt% to 50 wt% platinum group metal.

Embodiment 57. The method of any one of embodiments 34-56, wherein the catalytic nanoparticle has an average diameter between 1 nm and 10 nm.

Embodiment 58. The method of any one of embodiments 34-57, wherein the support nanoparticle has an average diameter of 10 nm to 20 nm.

Embodiment 59. The method of any one of embodiments 34-58, wherein the support nanoparticle comprises a metal oxide.

Embodiment 60. The method of embodiment 59, wherein the support nanoparticle comprises aluminum oxide, cerium oxide, zirconium oxide, lanthanum oxide, yttrium oxide, silica, neodymium oxide, or a combination thereof.

Embodiment 61. The method of embodiment 60, wherein the support nanoparticle comprises aluminum oxide and the catalytic material comprises platinum or palladium.

Embodiment 62. The method of embodiment 60, wherein the support nanoparticle comprises cerium oxide and the catalytic particle comprises rhodium.

Embodiment 63. The method of any one of embodiments 34-62, wherein the composite nanoparticles and the spacer nanoparticles are present in the catalytic material at a ratio of about 1 : 1 to about 1 : 50.

Embodiment 64. The method of any one of embodiments 34-63, wherein the spacer nanoparticles comprise a metal oxide. Embodiment 65. The method of embodiment 64, wherein the spacer nanoparticles comprise aluminum oxide, cerium oxide, zirconium oxide, lanthanum oxide, yttrium oxide, silica, neodymium oxide, or a combination thereof.

Embodiment 66. The method of any one of embodiments 34-65, wherein the spacer nanoparticles comprise aluminum oxide.

Embodiment 67. The method of any one of embodiments 34-66, wherein the support nanoparticle and the spacer nanoparticles are the same material.

Embodiment 68. The method of any one of embodiments 34-67, wherein the spacer nanoparticles and the porous carrier comprise the same material .

Embodiment 69. The method of any one of embodiments 34-63, wherein the spacer nanoparticles comprise boehmite.

Embodiment 70. The method of any one of embodiments 34-69, wherein the porous catalytic material comprises about 1 wt% to about 7 wt% platinum group metal.

Embodiment 71. The method of any one of embodiment 34-70, further comprising processing the resulting catalytic material into micron-sized particles.

Embodiment 72. The method of embodiment 71, wherein the resulting catalytic material is ground to form micron-sized particles.

Embodiment 73. A porous catalytic material made by the method of any one of embodiments 34-72.

Embodiment 74. A coated substrate comprising :

a substrate; and

a washcoat layer comprising catalytic material of any one of embodiments 1-33 and 73.

Embodiment 75. The coated substrate of embodiment 74, wherein the substrate comprises cordierite.

Embodiment 76. The coated substrate of embodiment 74 or 75, wherein the substrate comprises a honeycomb structure.

Embodiment 77. A catalytic converter comprising a coated substrate according to any one of embodiments 74-76. Embodiment 78. An exhaust treatment system comprising a conduit for exhaust gas and a catalytic converter according to embodiment 77.

Embodiment 79. A vehicle comprising the coated substrate of any one of embodiments 74-76, the catalytic converter of embodiment 77, or the exhaust treatment system of embodiment 78.

Embodiment 80. A washcoat composition comprising the catalytic material of any one of embodiments 1-33 and 73.

Embodiment 81. The washcoat composition of embodiment 80, wherein the washcoat composition comprises an aqueous medium at a pH between 3 and 5. Embodiment 82. A method of forming a coated substrate comprising coating a substrate with a washcoat composition according to embodiment 80 or 81.

Embodiment 83. The method of forming the coated substrate according to embodiment 83, the method further comprising calcining the substrate after coating with the washcoat composition.

Embodiment 84. A catalytic material comprising :

a plurality of composite nanoparticles comprising a support nanoparticle and a catalytic nanoparticle;

a plurality of non-catalytic spacer nanoparticles; and

a carrier that bridges together the composite nanoparticles and the spacer nanoparticles, wherein the carrier comprises a combustible component and a non-combustible component.

Embodiment 85. The catalytic material of embodiment 84, wherein the combustible component comprises a combustible gel.

Embodiment 86. The catalytic material of embodiment 84 or 85, wherein the combustible component comprises polymerized resorcinol.

Embodiment 87. The catalytic material of any one of embodiments 84-86, wherein the catalytic nanoparticle comprises at least one platinum group metal.

Embodiment 88. The catalytic material of embodiment 87, wherein the catalytic nanoparticle comprises rhodium. Embodiment 89. The catalytic material of embodiment 87, wherein the catalytic nanoparticle comprises platinum or palladium.

Embodiment 90. The catalytic material of embodiment 87 or 89, wherein the catalytic nanoparticle comprises platinum and palladium.

Embodiment 91. The catalytic material of any one of embodiments 87, 89, and 90, wherein the catalytic nanoparticle comprises platinum and palladium in a weight ratio of about 1 :2 platinum : palladium to about 25 : 1 platinum : palladium.

Embodiment 92. The catalytic material of any one of embodiments 87 and 89-91, wherein the catalytic nanoparticle comprises platinum and palladium in a weight ratio of about 2: 1 platinum : palladium to about 10 : 1 platinum : palladium.

Embodiment 93. The catalytic material of embodiment 87 or 89, wherein the catalytic nanoparticle comprises platinum and is substantially free of palladium. Embodiment 94. The catalytic material of embodiment 87 or 89, wherein the catalytic nanoparticle comprises palladium and is substantially free of platinum. Embodiment 95. The catalytic material of any one of embodiments 84-95, wherein the composite nanoparticles comprise about 10 wt% to 70 wt% platinum group metal.

Embodiment 96. The catalytic material of any one of embodiments 84-95, wherein the composite nanoparticles comprise about 30 wt% to 50 wt% platinum group metal.

Embodiment 97. The catalytic material of any one of embodiments 84-96, wherein the catalytic nanoparticle has an average diameter between 1 nm and 10 nm.

Embodiment 98. The catalytic material of any one of embodiments 84-97, wherein the support nanoparticle has an average diameter of 10 nm to 20 nm.

Embodiment 99. The catalytic material of any one of embodiments 84-98, wherein the support nanoparticle comprises a metal oxide.

Embodiment 100. The catalytic material of embodiment 99, wherein the support nanoparticle comprises aluminum oxide, cerium oxide, zirconium oxide, lanthanum oxide, yttrium oxide, silica, neodymium oxide, or a combination thereof. Embodiment 101. The catalytic material of embodiment 99 or 100, wherein the support nanoparticle comprises aluminum oxide and the catalytic material comprises platinum or palladium.

Embodiment 102. The catalytic material of embodiment 99 or 100, wherein the support nanoparticle comprises cerium oxide and the catalytic particle comprises rhodium.

Embodiment 103. The catalytic material of any one of embodiments 84-102, wherein the non-combustible component of the carrier comprises a metal oxide. Embodiment 104. The catalytic material of embodiment 103, wherein the non- combustible component of the carrier comprises aluminum oxide, cerium oxide, zirconium oxide, lanthanum oxide, yttrium oxide, silica, neodymium oxide, or a combination thereof.

Embodiment 105. The catalytic material of embodiment 103, wherein the non- combustible component of the carrier comprises aluminum oxide, the support nanoparticle comprises aluminum oxide, and the catalytic material comprises platinum or palladium.

Embodiment 106. The catalytic material of embodiment 104, wherein the non- combustible component of the carrier further comprises lanthanum oxide.

Embodiment 107. The catalytic material of embodiment 103, wherein the porous carrier comprises cerium oxide, the support nanoparticle comprises cerium oxide and the catalytic particle comprises rhodium.

Embodiment 108. The catalytic material of any one of embodiments 84-107, wherein the composite nanoparticles and the plurality of spacer nanoparticles are present in the catalytic material at a ratio of about 1 : 1 to about 1 : 50.

Embodiment 109. The catalytic material of any one of embodiments 84-108, wherein the catalytic material comprises about 1 wt% to about 7 wt% platinum group metal.

Embodiment 110. A method of producing a catalytic material comprising : mixing a plurality of composite nanoparticles and a plurality of non-catalytic spacer nanoparticles with a liquid comprising a carrier precursor, wherein the composite nanoparticles comprise a support nanoparticle and a catalytic nanoparticle; and solidifying the carrier precursor to form a solidified carrier that bridges together the composite nanoparticles and the non-catalytic spacer nanoparticles.

Embodiment 111. The method of embodiment 110, further comprising :

mixing a plurality of composite nanoparticles and a plurality of non-catalytic spacer nanoparticles prior to mixing the plurality of composite nanoparticles and the plurality of non-catalytic spacer nanoparticles with the liquid containing the carrier precursor.

Embodiment 112. The method of embodiment 110 or 111, wherein the carrier precursor is solidified to form a combustible component of the solidified carrier and a non-combustible component of the solidified carrier.

Embodiment 113. The method of any one of embodiments 110-112, further comprising stabilizing the carrier with a stabilizing metal oxide.

Embodiment 114. The method of embodiment 113, wherein the stabilizing metal oxide is lanthanum oxide.

Embodiment 115. The method of embodiment 113 or 114, wherein the carrier is stabilized by adding a stabilizing metal oxide precursor solution to the catalytic material, drying the catalytic material, and calcining the catalytic material .

Embodiment 116. The method according to any one of embodiments 110-115, wherein the non-combustible component comprises aluminum oxide, cerium oxide, zirconium oxide, lanthanum oxide, yttrium oxide, silica, neodymium oxide, or a combination thereof.

Embodiment 117. The method according to embodiment 115 or 116, wherein the non-combustible component comprises aluminum oxide and lanthanum oxide. Embodiment 118. The method of any one of embodiments 110-117, wherein the carrier precursor is solidified by polymerization.

Embodiment 119. The method of any one of embodiments 110-118, wherein the combustible component comprises a combustible gel. Embodiment 120. The catalytic material of embodiment 118 or 119, wherein the combustible component comprises polymerized resorcinol.

Embodiment 121. The method of any one of embodiments 110-120, wherein the catalytic nanoparticle comprises at least one platinum group metal.

Embodiment 122. The method of any one of embodiments 110-121, wherein the catalytic nanoparticle comprises rhodium.

Embodiment 123. The method of any one of embodiments 110-121, wherein the catalytic nanoparticle comprises platinum or palladium.

Embodiment 124. The method of any one of embodiments 110-123, wherein the catalytic nanoparticle comprises platinum and palladium.

Embodiment 125. The method of embodiment 124, wherein the catalytic nanoparticle comprises platinum and palladium in a weight ratio of about 1 :2 platinum : palladium to about 25 : 1 platinum : palladium.

Embodiment 126. The method of embodiment 124 or 125, wherein the catalytic nanoparticle comprises platinum and palladium in a weight ratio of about 2 : 1 platinum : palladium to about 10 : 1 platinum : palladium.

Embodiment 127. The method of embodiment 121 or 123, wherein the catalytic nanoparticle comprises platinum and is substantially free of palladium.

Embodiment 128. The method of embodiment 121 or 123, wherein the catalytic nanoparticle comprises palladium and is substantially free of platinum.

Embodiment 129. The method of any one of embodiments 110-128, wherein the composite nanoparticles comprise about 10 wt% to 70 wt% platinum group metal. Embodiment 130. The method of any one of embodiments 110-129, wherein the composite nanoparticles comprise about 30 wt% to 50 wt% platinum group metal . Embodiment 131. The method of any one of embodiments 110-130, wherein the catalytic nanoparticle has an average diameter between 1 nm and 10 nm.

Embodiment 132. The method of any one of embodiments 110-131, wherein the support nanoparticle has an average diameter of 10 nm to 20 nm.

Embodiment 133. The method of any one of embodiments 110-134, wherein the support nanoparticle comprises a metal oxide. Embodiment 134. The method of embodiment 133, wherein the support nanoparticle comprises aluminum oxide, cerium oxide, zirconium oxide, lanthanum oxide, yttrium oxide, silica, neodymium oxide, or a combination thereof.

Embodiment 135. The method of embodiment 133 or 134, wherein the support nanoparticle comprises aluminum oxide and the catalytic material comprises platinum or palladium.

Embodiment 136. The method of embodiment 133 or 134, wherein the support nanoparticle comprises cerium oxide and the catalytic particle comprises rhodium. Embodiment 137. The method of any one of embodiments 110-136, wherein the plurality of composite nanoparticles and the plurality of non-catalytic spacer nanoparticles are present in the catalytic material at a ratio of about 1 : 1 to about 1 : 50.

Embodiment 138. The method of any one of embodiments 110-137, wherein the catalytic material comprises about 1 wt% to about 7 wt% platinum group metal . Embodiment 139. A catalytic material made by the method of any one of embodiments 110-138.

EXAMPLES

The following Examples are provided to illustrate, but are not intended to limit, the invention.

Example 1

The following methods were used to produce micron-sized catalytic material including non-catalytic aluminum oxide spacer nanoparticles, composite

nanoparticles containing an aluminum oxide support particle and a catalytic particle containing a platinum and palladium alloy, and a porous carrier that bridges together the composite nanoparticles and the spacer nanoparticles.

13.3 wt% Alu C (Evonik) aluminum oxide nanoparticles was dispersed in 95% denatured ethanol with 6.67 wt% DisperBYK ^® -145 and 0.05 wt% Samrcok antifoam. The mixture was sonicated to disperse the spacer nanoparticles. Separately, 6 wt% composite nanoparticles (40 wt% catalytic nanoparticle containing a 2.1 : 1 ratio of platinum to palladium, and 60 wt% aluminum oxide support nanoparticle) was mixed with deionized water with 3 wt% Jeffspere® x3503 and 0.05 wt% Shamrock antifoam. The mixture was sonicated to disperse the composite nanoparticles.

1072 g of the spacer nanoparticle suspension (13.3 wt% Alu C) was mixed with 178 g of the composite nanoparticle suspension (6 wt% composite nanoparticles) was combined and homogenized for 5 minutes.

A gel activation solution was formed by mixing 250 g of propylene oxide with 150 g of 37 wt% formaldehyde solution water, and mixing for 5 minutes. The gel activation solution was mixed with the nanoparticle suspension (containing the spacer nanoparticles and the composite nanoparticles) for 5 minutes. A gel precursor solution was separately made by mixing 300 g of denatured 95% ethanol with 100 g resorcinol and 90 g aluminum nitrate nonahydrate for 30 minutes until the material was dissolved. The gel precursor solution was then mixed with the mixture of gel activation solution and nanoparticles for 15 minutes.

The final mixture was placed in a container and heated to 60 °C for about 72-96 hours, during which time the gel polymerizes and dries, thereby forming a catalyst material containing a combustible portion and a non-combustible portion that bridges together the spacer nanoparticles and the composite nanoparticles. The dried catalyst material was removed from the drying oven and calcined in a furnace ramped to 550 °C at a rate of 6.7 °C/min, with a hold time at 550 °C for 20 hours. During the calcination process, the combustible portion of the carrier was burned off an exhausted. The resulting porous catalytic material was powdered in a grinder into micron-sized particles.

Example 2

Micron-sized catalytic material containing Alu C spacer nanoparticles and composite nanoparticles (40 wt% catalytic nanoparticle containing 2.1 : 1 ratio of platinum to palladium, 60 wt% aluminum oxide support nanoparticles) bridged together by a porous aluminum oxide carrier was suspended in water to form a washcoat composition . Boehmite particles were also added to the washcoat composition to form about 5 wt% of the solids in the washcoat composition (with the remaining 95 wt% being micron-sized catalytic particles) . The washcoat composition was used to coat a substrate, which was dried and calcined . The resulting coated substrate had a platinum group metal loading of 2.03 g/L.

Separately NNiM powder (as described in U .S. Patent Pub. No. 2015/0140317) containing composite nanoparticles (3 wt% catalytic nanoparticle containing 1.8 : 1 platinum to palladium, and 97 wt% aluminum oxide particles) bridged together by a porous aluminum oxide carrier was suspended in water to form a washcoat composition . Boehmite particles were also added to the washcoat composition to form about 5 wt% of the solids in the washcoat composition (with the remaining 95 wt% being micron-sized catalytic particles) . The washcoat composition was used to coat a substrate, which was dried and calcined. The resulting coated substrate had a platinum group metal loading of 2.05 g/L.

A synthetic exhaust gas containing propene (60 ppm), CO (900 ppm), NO ( 110 ppm), 02 ( 12.5%), C02 (6%), H20 (6.5%), and N2 (balance) was passed through the coated substrates at a GHSV of 30,000 h- 1, and the amount of CO and propene exiting the coated substrate was measured. The temperature of the gas was ramped at a rate of 9 °C from 25 °C to 425 °C. The coated substrate containing NNiM particles had a CO light off temperature of 149 °C and a hydrocarbon light off temperature of 149 °C. The coated substrate containing the micron-sized catalytic material particles containing Alu C spacer nanoparticles and composite

nanoparticles (40 wt% catalytic nanoparticle containing 2.1 : 1 ratio of platinum to palladium, 60 wt% aluminum oxide support nanoparticles) bridged together by a porous aluminum oxide carrier had a CO light off temperature of 145 °C and a hydrocarbon light off temperature of 147 °C. The present invention has been described in terms of specific embodiments incorporating details to facilitate the understanding of principles of construction and operation of the invention . Such reference herein to specific embodiments and details thereof is not intended to limit the scope of the claims appended hereto. It will be readily apparent to one skilled in the art that other various modifications can be made in the embodiments chosen for illustration without departing from the spirit and scope of the invention . Therefore, the description and examples should not be construed as limiting the scope of the invention .