FIELD OF THE DISCLOSURE . [0002] This present disclosure relates to methods for treating surfaces of a hydrogen generation reactor chamber. In particular, the disclosure relates to treatment of a hydrogen generation chamber.

DESCRIPTION OF RELATED ART [0003] The growing popularity of portable electronic devices has produced an increased demand for compact and correspondingly portable electrical power sources to energize these devices. Fuel cells in general and particularly hydrogen/air fuel cells (H/AFCs) have enormous potential as a replacement for batteries. Many types of fuel cells are known in the art, which use hydrogen for fuel.

[0004] A hydrogen generation reactor chamber is therefore generally provided to operate the cell. Many different kinds of reactions resulting in hydrogen production can be performed in the chamber. Suitable exemplary reactions include cracking of ammonia, processing hydrocarbons, such as methane (natural gas), propane, butane, liquid fuels such as gasoline, diesel and JP-8, and oxygenates such as methanol.

[0005] The choice of the fuel and the choice of the method of processing the fuel, e. g. steam reforming, partial oxidation, and autothermal reforming, depends to a large extent on the type of service, such as portable, stationary or automotive fuel cell power systems.

[0006] Catalysts are usually deposed into the chamber. In particular, an appropriate catalyst is typically deposed in the hydrogen generation reactor chamber to increase the rate of the reaction. The activity and the life of the catalyst depends on many factors, such as the method of deposition, the surface of the chamber where the catalyst is deposed and the form in which it is deposed (powder or coatings).

SUMMARY OF THE DISCLOSURE [0007] The present disclosure provides a method for depositing a catalyst onto surfaces of an hydrogen generation chamber, in a mixture wherein particles of the catalyst are included together with a gas and, optionally, with particles of other materials. In the method, the mixture is applied to a surface at an application temperature and with an application kinetic energy such that at least part of the particles mechanically deform upon application of the mixture onto a surface.

[0008] According to a first aspect, a method for depositing a catalyst, into a hydrogen generation reactor chamber, which comprises a substrate surface, is disclosed.

[0009] The method comprises applying to the substrate surface of the chamber a mixture comprising particles of the catalyst and a gas, at an application temperature and at an application kinetic energy causing bonding of the particles to the substrate surface, wherein the particles have a melting temperature and the application temperature is lower than the melting temperature.

[0010] According to the first aspect, at least part of the particles of catalysts in the mixture mechanically deform upon application of the mixture at the application temperature and at the application kinetic energy.

[0011] The mixture could also include other materials, such as ductile materials which mechanically deform upon application of the mixture at the application temperature and at with an application kinetic energy improving bonding of the catalyst to the substrate surface.

[0012] According to a second aspect a method for depositing a catalyst into a hydrogen generation reactor chamber comprising a substrate surface, is disclosed.

[0013] The method comprises applying to the substrate surface a mixture comprising particles of the catalyst, particles of a ductile material and a gas, at an application temperature and with an application kinetic energy causing bonding of the particles to the substrate surface, wherein the application temperature is lower than the melting temperature of the particles of the catalyst and of the particles of ductile material.

[0014] According to the second aspect, the particle component of the mixture to be applied further comprise particles of ductile material that deform upon application of the mixture onto the substrate surface at the application temperature and at the application kinetic energy causing and/or improving bonding of the catalyst to the surface.

[0015] According to a third aspect, a method for depositing a catalyst into a hydrogen generation reactor chamber, which comprises a substrate surface, is disclosed.

[0016] The method according to the third aspect comprises: applying to the substrate surface a first mixture, the first mixture comprising particles of a ductile material and a gas, obtaining a first treated substrate surface; and applying to the first treated substrate surface a second mixture, the second mixture comprising particles of the catalyst and a gas, at an application temperature and with an application kinetic energy causing bonding of the particles to the substrate surface, wherein the application temperature is lower than the melting temperature of the particles of the catalyst.

[0017] According to the third aspect, at least one between the particles of the catalyst and particles of a ductile material mechanically deform upon application of the second mixture onto the substrate surface causing bonding of the catalyst to the first treated surface.

[0018] A catalyst according to the present disclosure is substance that enables a chemical or physical reaction to proceed at a usually faster rate or under different conditions than otherwise possible.

[0019] In particular, a catalyst can be any substance able to catalyze a reaction resulting in hydrogen production, such as steam reforming, autothermal reforming, partial oxidation, cracking ammonia, combustion, water gas shift or methanation or preferential oxidation.

[0020] Also a catalyst according to the present disclosure include any substance able to reduce carbon deposition during hydrogen generation reaction such as an alkaline oxide or oxides doped with alkali or alkaline earth metals mixed with a metal, preferably selected form the group consisting of noble metals and alkaline metals.

[0021] An advantage of the method disclosed is that the catalytic particles to be deposited have less tendency to sinter, volatilize, or oxidize and to lose their activity after deposition.

[0022] A further advantage is that the method herein disclosed does not require reduction in size of the particles to be deposited, as would be normally required when catalysts are deposited by conventional techniques such as washcoating.

[0023] An additional advantage of the method is that it reduces occurrence of undesirable interactions between dissimilar components (e. g. oxides and metal) at those temperatures, and this affords an efficient deposition of mixture wherein more than one catalyst and/or other materials are included.

[0024] In a preferred embodiment, a substance able to catalyze a reaction resulting in hydrogen production can be included in the mixture together with a substance able to reduce carbon deposition during hydrogen generation reaction, which is particularly advantageous when the hydrogen producing reaction results in carbon deposition.

[0025] Accordingly, catalyst formulations to be advantageously applied in the mixture can be composed of transition metal compounds, that include but are not limited to nickel and iron, noble metals that include, but are not limited to platinum, palladium and rhodium or combinations thereof, alone or together with alkaline oxide or oxides doped with alkali or alkaline earth metals.

[0026] A gas according to the present disclosure is a fluid that has neither independent shape nor volume but tends to expand indefinitely.

[0027] A ductile material according to the present disclosure is any substance in the mixtures and/or onto the substrate surface of the present disclosure that is able to mechanically deform upon application of the mixtures of the disclosure onto the substrate surface.

[0028] Substrate surface of the hydrogen generating reaction chamber can be any surface of the chamber, such as surfaces located inside the chamber (which includes surfaces of the reaction chamber and surfaces of the combustion chamber) or surfaces located inside structures connected to the chamber such as ports, tubes support surface, if any, as well as cover and/or a separation membrane. Substrate surface can also be a support surface, which if present, can have the form of a strip mountable in the chamber and can comprise at least one of metal foams, mesh, felts, ceramic monoliths, foams, or channels or flow. Preferably, substrate surface comprises mesochannels, i. e. channels or flow having dimensions between 0.3 mm and 2.5 mm and more preferably between 0.5 mm and 2.0 mm.

[0029] Preferred surfaces are inner surfaces of the tube, inner surfaces of the port, and, when the tube protrudes into the hydrogen generation reactor chamber, also outer surfaces of the tube. The mixture can be applied to one or more surfaces contemporaneously or at different time.

[0030] In particular embodiments, spray coating to coat the walls, base of the box or chamber, etc, can be applied, in order to leave an uncoated perimeter for joining using welding and other joining techniques.

[0031] In all the methods above, the hydrogen generation reactor chamber can be comprised of at least one of austenitic steels, titanium and high temperature refractory alloys suitable for hydrogen generation.

[0032] Other features and advantages of the present invention will be set forth in the following description and accompanying drawings, where the preferred embodiments of the present invention are described and shown. Additional details will become apparent to those skilled in the art upon examination of the detailed description taken in conjunction with the accompanying drawings or may be learned by practicing the present invention. The advantages of the present invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appendent claims.

BRIEF DESCRIPTION OF THE DRAWINGS [0033] Figure 1 shows a perspective view of an open metal reactor chamber with a cover and a hydrogen separation membrane on the side.

[0034] Figure 2 shows a cross-sectional view of the chamber shown in Figure 1 along line 2-2 during exposition to a cold spray.

[0035] Figure 3 shows the cross-sectional view of the chamber shown in FIG. 2 after exposure to the cold spray.

DETAILED DESCRIPTION [0036] The present disclosure refers to a method to deposit particles of a catalyst on surfaces of a hydrogen generation reactor chamber, which uses the kinetic energy of particles to cause bonding of the particles to a surface.

[0037] In the method disclosed herein, the particles are sprayed at high velocity towards a substrate surface of the reaction chamber and bounded to the substrate surface through high speed plastic deformation of the interacting bodies.

[0038] A substrate surface as herein disclosed is each and every surface of the reaction chamber wherein particles of the catalyst can be applied.

[0039] The spraying and bonding of the particles to the substrate surface is in particular performed at a temperature which is lower than the melting temperature of the particles, according to a technique extensively described in U. S. patent 5,302, 414, incorporated herein by reference in its entirety, also denominated"cold spray".

[0040] Mixtures including particles of one or more catalysts can be applied with the method herein disclosed to one or more surfaces of the hydrogen generating reactor, including surfaces of reaction chamber, combustion chamber, structures connected to the chambers as well as surfaces of a cover, a separation membrane and/or a substrate.

[0041] Embodiments of the method to deposit particles to substrate surfaces will be illustrated making also reference to Figures 1 to 3.

[0042] Figure 1 shows a reactor chamber (100) depicted in an open state with a cover (110) and a separation membrane (112) on the side. The reactor chamber (100) comprises a floor (102) and a side wall (104) surrounding the floor (102). The chamber has an inner surface (106), which comprises a principal surface (200) and any surfaces defined by or within the reaction chamber (100).

[0043] The reaction chamber (100) is a box having a rectangular shape.

However, to be used in the methods herein disclosed, the reaction chamber may have any suitable geometry for a hydrogen generation chamber. For example, large diameter tubular reactors, e. g. tubing of any length having diameters greater than 5 inches, or tubing of about 5 inches having diameters < 2 inches, can be used in the methods disclosed herein. Other shapes and geometry of tubular reactors as well as shapes and geometry of other kinds of hydrogen generation chambers are identifiable by a person skilled in the art upon reading of the present disclosure.

[0044] In any case, the method of the disclosure is particular well suited to the incorporation of catalysts in a micro-reactor architecture as well as in lab-scale or industrial tubular reactors.

[0045] Ports (107) are formed in the side wall (104) by tubes (108) which communicate through the reaction chamber (100) from the inside to the outside of the chamber in any configuration known to those of ordinary skill in the art.

[0046] A support structure can be placed in the reaction chamber. The support structure can be made of metal foams, mesh or felts, ceramic monoliths or foams, or mesochannels and can be mounted or formed as part of the reactor chamber (100) before the cover (110) is attached. The support structure can be a mountable strip formed of a base substrate with a catalyst support. In one embodiment, support structure formed by one or more strips is mountable into the chamber and two or more strips can be mounted in a predetermined configuration to form flow channels.

[0047] The reaction chamber (100) as wells tubes (108) and ports (107) are usually constructed out of metal substrates. Typically, reactor materials are chosen to accommodate operating temperatures. For low temperature operation such as methanol reforming (< 300 °C), aluminum can be utilized.

[0048] Other suitable metal substrates include stainless steel (austenitic steels such as Type 304,316, 321,330), Inconel@, titanium or other refractory alloys suitable for high temperature applications such as Hastelloye grade alloys. inconele refers to a family of trademarked high strength austenitic nickel-chromium-iron alloys that have exceptional anti-corrosion and heat-resistance properties.

[0049] Exemplary alloys include cast stainless steel such as HK (nominal composition of essential elements: C 0.2-0. 6, Mn 2.0 max, Si 2.0 max, Cr 24-28, Ni 18-22, Fe bal), Inconel 600 (nominal composition of essential elements: Ni (+Co) 76.4 C 0.04, Mn 0.2, Fe 7.2, S 0.007, Si 0.2, Cu 0.10 Cr 15.85), Inconel 625 (nominal composition of essential elements: Ni (+Co) 62.6, C 0.05, Mn 0.55, Fe 6.85, S 0.007, Si 0.35, Cu 0.005 Cr 20, Al 0.15, Ti 0.3, Cb (Ta) 3.95), Inconel X (nominal composition of essential elements: Ni (+Co) 72.85, C 0.04, Mn 0.65, Fe 6.80, S 0.007, Si 0.3, Cu 0.005, Cr 15.15, Al 0.75, Ti 2.5, Cb (Ta) 0.85) ; Hastelloy C (nominal composition of essential elements: Ni bal, Mo 16, Cr 16, Fe5, W4, Mn, Si), Hastelloy G (nominal composition of essential elements : Ni 44, Cr, 22, Fe 20, mo 6.5, Cb+Ta 2.1, Cu 2.0, C0. 05 max, W 1 max) and Hastelloy X (nominal composition of essential elements: Co 1.5 max, Fe 18.5, Cr 22.0, Mo 9.0, W 0.6, C 0.15 max (wrought), C 0.2 max (cast), Ni bal) or other Haynes type alloys, Inconel 617: (nominal composition of essential elements: C 0.05 min, Co 10.0 min, Cr 20.0 min, Mo 8.0 min, Al 0.80 min, Ni balance) or Alloy 253 MA: (nominal composition of essential elements : C 0.05 min, Ce 0.03 min, Cr 20 min, Mn 0.8 max, Ni 10 min, N2 0.14 min, P 0.04 max, Si 1.4 min, S 0.03 max, Fe balance).

[0050] Other alloys and metal substrates can be used to construct reaction chambers and tubes suitable in the methods herein disclosed and are identifiable by a person skilled in the art.

[0051] The inner surface of the reaction chamber, any surface of the tube (108), of the port (107), of the cover (110), particularly on the internal surface thereof, of the separation membrane (112) and of the support structure constitutes examples of substrate surfaces of the reaction chamber as disclosed herein. In [0052] In one embodiment, treatment of the inner surface (106) is performed when the chamber (100) is in an open state. In particular, treatment of the metal substrate forming the inner surface (106) of the reactor chamber (100) and/or the inner surfaces of the ports (107) comprises modifying the metal substrate by exposing the metal substrate to a cold spray containing particle materials. In some instances, the tube (108), comprising ports (107), may protrude into the reactor chamber (100) and external surfaces of the tube (108) can also be treated in the same way. In embodiments where catalyst is included in a support structure, treatment of the support structure can be performed before or after the support structure is mounted in the chamber. In particular, when the support is a strip it can be formed of a base substrate with a catalyst support, or of the catalyst support alone. The strips can be coated and then mounted, or the uncoated strips can be mounted in the chamber and then coated with the catalyst. The strips can be disposed in the chamber according to any order described in US 10/404,882 incorporated herein by reference in its entirety.

[0053] In particular, application of a cold spray stream (300) on the inner surface (106) of the reaction chamber (100) as shown in Figure 1 by arrows is better explained in the enlarged cross sectional view of Figure 2.

[0054] The cold spray stream (300) is composed of a mixture that includes a gas component (215) and a particle component (210) that comprises particles of a catalyst. In the example of Figure 2, the mixture including the particle component (210) and the gas component (215) is deposited by the cold spray stream (300) on the substrate surface constitute by the principal surface (200) of the reaction chamber corresponding to the principal surface (102) of Figure 1.

[0055] The cold spray stream (300) is usually originated by subjecting the gas component (215) and the particle component (210) to pressure typically resulting in a high-velocity flow of the particle component (210) in solid state. In particular, the gas- particle mixture in the cold spray stream (300) is imparted at an application temperature that is lower than the melting temperature of the particle of catalyst and with velocities providing adequate application kinetic energy to the sprayed material to cause bonding.

[0056] Preferred application temperatures are in the range from ambient temperature to 700 °C. Preferred application kinetic energies are associated with a velocity of the particles in a range from 300 to about 1200 m/s.

[0057] The kinetic energy of the impact of the particle component (210) on the substrate surface is spent for high-speed plastic deformation of the interacting particles and substrate surface. Accordingly, at least one of the particle component (210) and substrate surface must comprise a material (ductile material) that mechanically deforms upon application of the mixture at the application temperature and at the application kinetic energy causing bonding of the particles of a catalyst in the particle component (210) to the substrate surface.

[0058] In one embodiment, the particles of catalyst to be applied to the substrate surface mechanically deform upon application of the mixture that include them at the application temperature and at the application kinetic energy so that the catalyst itself constitute a ductile material and no additional ductile material is required to cause bonding of the catalyst onto the substrate surface.

[0059] In another embodiment, an additional ductile material is provided to enable and/or improve bonding of the particles of the catalyst to be deposited onto the substrate surface. In particular, the additional ductile material can be included in the particle component (210) of the cold spray stream (300) and/or provided on the substrate surface.

[0060] In embodiments wherein additional ductile material is provided in the particle component (210) of the mixture, the ratio between particles of ductile material and other particles of the particle component (210) needs to be determined for each application.

[0061] Preferably, in embodiments wherein the mixtures include particles able to mechanically deform upon application of the mixture at the application temperature and with the application kinetic energy, constitute >50% wt% of the particle component of the mixture.

[0062] In embodiments wherein an additional ductile material is provided on the substrate surface, the additional ductile material can be constituted by the constituent material of the substrate surface and/or by material applied to the substrate surface before application of the particles of a catalyst. In the latter case, the ductile material can be applied by a cold spray stream or by any other suitable technique.

[0063] In any case, upon application by the cold spray stream (300) particles of at least one catalyst present in the particle component (210) are bonded to the substrate surface in a way allowing the particles of the catalyst to retain their chemical activity.

[0064] According to one embodiment, the particles of the catalyst include particles of one or more catalysts to be applied to the substrate surface of the reaction chamber.

[0065] Any catalyst suitable to catalyze reactions maximizing and/or however resulting in hydrogen production can be applied using a cold spray (300). Exemplary reactions performed in a hydrogen reaction chamber include but are not limited to steam reforming, combustion, water gas shift and methanation, autothermal reforming, partial oxidation, cracking ammonia, or preferential oxidation.

[0066] In particular, catalyst formulations can be composed of transition metal compounds that include but are not limited to nickel and iron, noble metals that include, but are not limited to platinum, palladium and rhodium, or combinations thereof.

[0067] According to another embodiment the particles of the catalyst comprise particles of material for reducing carbon deposition during hydrogen generation (anti- coking material), alone or in addition to the particles able to catalyze reactions resulting in hydrogen production.

[0068] An example of a suitable material for reducing carbon deposition in a hydrogen generation reactor chamber is alumina doped with alkali metal or alkaline earth components. For example, Saint-Gobain Norpro (Akron, OH) provides an exemplary support material that contains the following: > 92% alumina, 0.55% Silica, 4.5% CaO and 1% MgO. Alumina containing potassium in the form of kalsilite may also be used. These dopants promote steam adsorption during reforming and thus carbon gasification reactions. For example, doped alumina powder having a size of about 1 to about 50 microns can be used.

[0069] Catalysts to be applied by the method herein disclosed can also include material minimizing corrosion to be applied to the substrate surface to of the reaction chamber to provide a corrosion resistance coating and high-activity steam reformation catalysts, steam reformation catalysts that promote a water-gas shift reaction and a coke-resistant steam reformation catalysts. Other catalysts identifiable by the person skilled in the art upon reading of the present disclosure can be applied with the method herein disclosed and will not be described in further details.

[0070] Catalysts can be deposited directly on a substrate surface in the reaction chamber, and the substrate surface, comprises each and every surface of the reaction chamber wherein the catalyst, can be applied. In some instances, the catalysts may be packed into the reactor in the form of particles or pellets ; the mesochannels may also be packed with catalyst powders.

[0071] Particles of ductile material that can be included the mixture to be applied by the cold spray stream (300) and/or onto the substrate surface, can be particles of any material that mechanically deform at the application temperature and at the application kinetic energy.

[0072] An example of ductile material is given by transition metals or mixture thereof, preferably containing minor quantities of noble metals (such as gold, silver, platinum, rhodium, palladium, ruthenium, osmium, and iridium). A percentage of between about 50% and about 90% metal in the particle component of the gas- particles mixture is suitable.

[0073] Another example of ductile material is given by doped alumina-metal precursor to be included in a particle component (210) for example as a physical mixing of doped alumina and metal powders.

[0074] The ductile material can have a chemical activity, such as catalytic activity (transition metals, noble metals) or coking formation reducing activity (e. g. alkaline oxide or oxides doped with alkali or alkaline earth metals mixed with a metal, wherein the oxide component could include, but is not limited to alumina, silica, titania, ceria or combinations thereof).

[0075] The gas (215) can include any suitable carrier gases for cold spray application such as air, nitrogen, helium as practiced by the KTech Corporation of Albuquerque, NM.

[0076] Exemplary preferred mixtures to be applied in the cold spray stream (300) include a first mixture including a catalyst such as catalysts, particularly when constitute by noble metals, and anti-coking material and other material such as metal powders in a gas such as nitrogen or helium ; a second mixture comprising a catalyst, particularly when constituted by non-noble metals, and anti-coking, material in a gas such as nitrogen or helium ; a third mixture comprising a catalyst, particularly when constituted by non-metals, and anti-coking material, and other material such as metal powders in a gas such as nitrogen or helium.

[0077] In the above three examples, the metal component needed to provide ductility would constitute greater than about 50% of the particle component in the gas mixture. The metal component may be a catalyst material or non-catalyst material. Non-noble metal catalysts can constitute from about 5 to about 20% of the particle component in the gas mixture. Noble-metal components can constitute from about 0. 5% to about 5% of the particle component in the gas mixture. Anti-coking materials can constitute from about 5 to about 20% of the particle component in the gas mixture.

[0078] As a result the catalysts of the above mixtures can be deposited on a substrate surface as a coating.

[0079] Figure 3, shows the cross section of the principal surface (200) after cold spray treatment. A coating (211) is formed on the principal surface (200) resulting in a coated principal surface (220). Such coating include the catalyst, which may include for example a catalyst, anti-coking material and/or support material, depending on the embodiment and the result desired.

[0080] After cold spray treatment, the cover (110) is then added to the chamber to close off the reactor chamber (100) during operation. In some instances, the cover (110) may also incorporate the hydrogen separation membrane (112).

[0081] The gas pressure, gas temperature, powder feed rate, translational velocity of the nozzle across the substrate are all variables that influence coating of the catalyst. Some typical ranges are as follows : gas pressure: from about 100 to about 500 psi: application temperature: from ambient temperature to about 700 °C ; gas flow rate: from about 30 to about 100 cfm (cubic feet/min); powder feed rate: from about 10 to about 30 Ibs/h, wherein powder feed rate refers to the particle component of the mixtures.

[0082] Dimension of the particles varies depending on the catalyst used and the intended applications. For example, an active catalyst having a particle size in a range from about 5 to about 10 pm can be applied using the cold spray technique which is also well suited for mass production. The dimensions of the catalyst particles are typically in a range from about 1 to about 50 microns, irrespective of the catalyst formulations. It is more or less an artifact of the process. More preferably in a range from about 5 to 20 microns range.

[0083] The particles that are not deposited on the substrate can be recovered using a particle recovery system, such as cyclone separators and filters. This system allows costly components such as noble metals to not get wasted.

[0084] In embodiments wherein an additional ductile material is provided, the ductile material can be included in the particle component (210) of the cold spray stream (300) or provided on the substrate surface.

[0085] For example, in one embodiment, ductile materials, consisting of metal powders mixed with such as alkaline oxide or oxides doped with alkali or alkaline earth metals, are first deposited on the substrate surface, for example constitute by metal surfaces. The metal component of the ductile material could be the same as the metal of the reactor metal component. The thickness of the first deposited layer would preferably be in a range from about 5 to about 100 micron.

[0086] On to the first deposited layer, a second layer can be deposited, wherein the second layer can consist of formulations comprising a catalyst, for example transition metal compounds that include but are not limited to nickel, iron, ruthenium.

Other catalysts such as, noble metals that include, but are not limited to platinum, palladium or rhodium or combinations thereof could be deposited as well. The second layer could also be composed of materials such as carbides (e. g. molybdenum carbide) which under certain conditions mimic the behavior of noble metal components.

[0087] In another exemplary embodiment, the materials constituting the first and second deposited layers in the previous example can be mixed and deposited as a single layer. In particular, the operation of applying to the substrate surface the mixture comprising the particles to be applied (catalyst, ductile material, and/or other material), can be preceded by mixing the particles to provide the particle component of the mixture and thereafter mixing the particle component with the gas to obtain the mixture.

[0088] Since, according to the disclosure, the catalyst is coated directly on the substrate surfaces of the reaction chamber, this can result in improved reaction rates as a result of factors such as negligible mass transfer resistances and improved heat transfer between the feed (or reactants) and the catalyst surface and between the hot metal surfaces and the catalyst surface. As a consequence, for a given hydrogen production rate, the size of the reaction chamber can be dramatically reduced.

[0089] The method disclosed herewith allows performing coating of catalyst in a less labor intensive way than conventional wash coating methods and can be cost effective particularly for large scale or large volumes of small scale devices.

[0090] In addition, different parts of the reaction chamber can be coated with different catalysts formulations, such as different catalysts formulations applied to different surfaces of the reaction chamber to favor different reactions.

[0091] For example, a water gas shift formulation can be deposited in areas wherein the temperature is below 400 °C and a preferential oxidation or methanation formulation can be deposited in areas wherein the temperature is below 200 °C.

Also, if the feed contains impurities such as sulfur containing compounds like H2S, a portion of the reactor chamber or a separate reactor chamber can be coated with formulations that contain nickel, zinc, copper or other materials that exhibit a tendency to trap or otherwise remove these impurities before the feed is exposed to the catalyst region in which hydrogen generation occurs.

[0092] Also different mixtures comprising a plurality catalysts can be applied to different substrate surfaces of the reaction chamber to provide a staged catalyst medium, as described in US 60/561,750 (incorporated herein by reference in its entirety), through which a feed stream of hydrocarbons is passed to liberate hydrogen.

[0093] In particular, mixtures can be prepared so that each plurality of catalyst to be applied posses unique definitive characteristics and catalytic propertied. The mixtures can then be applied on substrate surfaces of the reactor to provide a staged catalyst medium through which a feed stream of hydrocarbons is passed to liberate hydrogen.

[0094] In some embodiments the plurality of catalyst are packed/loaded within the hydrogen reactor chamber such that a feed stream of hydrocarbons is exposed to the plurality of catalyst in a predetermined sequential manner.

[0095] For example, the predetermined sequential presentation manner can include depose the plurality of catalyst in the reaction chamber in a manner such that the introduced feed stream of hydrocarbons contacts a steam reformation catalyst which promotes a water-gas shift reaction, located adjacent entrance or, typically exit portions of the hydrogen reactor chamber.

[0096] In other embodiments, the packing of the plurality of catalyst powders within the hydrogen reactor chamber is provided such that staged catalyst medium includes a first portion having at least one of a high-activity steam reformation catalyst and a coke-resistant steam reformation catalyst and a second portion having a steam reformation catalyst that promotes a water-gas shift reaction, located adjacent exit portion of the hydrogen reactor chamber.

[0097] In still one further embodiment, a coke-resistant steam reformation catalyst is loaded at an entrance of the hydrogen reactor chamber, followed by a high-activity steam reformation catalyst or wherein all or part of the coke-resistant steam reformation catalyst is mixed with the high-activity steam reformation catalyst before loading into the hydrogen reactor chamber.

[0098] In any case, coatings of catalysts can be applied at temperatures below 700 °C, to insure the integrity of the catalytic components that are used for the hydrogen generation. That is, the particles to be deposited have less tendency to sinter, volatilize, or oxidize and to lose their activity after deposition. The cold spray method allows for coatings to be deposited at temperatures ranging from ambient to 700 °C.

[0099] The mixtures herein disclosed can be produced by physically mixing the particles to produce an homogeneous particles mixture. Subsequently the particles mixture can be mixed with the gas, for example by loading the particles mixture into a hopper and placing the particle mixture in contact with the gas in a nozzle. The mixture comprising particles and gas is then entrained to impact the substrate surface.

[00100] The following examples are provided to describe the invention in further detail. These examples, which set forth a specific mode presently contemplated for carrying out the disclosure, are intended to illustrate and not to limit the invention EXAMPLES [00101] Experiments were setup to deposit 99.9% pure molybdenum and mixtures by weight percent of 99.9% iron and 99.5% molybdenum carbide in compositions shown below. These powders were deposited onto planar Inconel substrates 0. 4" x 3"x 1/8"thick. The powders consisted of 90 wt. % Fe-10 wt. % MoC, 75 wt. % Fe- 25 wt. % MoC, and 50 wt. % Fe-50 wt. % MoC.

[00102] The composite powders were thoroughly mixed to produce a homogeneous mixture. The size cut of all the powders was-25/+5 pm. Samples of the powder were taken analyzed for particle size distribution.

[00103] The coating thickness was to be between 0.001 and 0.002 inches. Due to the thin coating required, each Inconel substrate was weighed and the initial thickness was measured prior to spraying. After spraying, the substrate was weighed and thickness measurements measured along the length with a digital micrometer and recorded.

[00104] Tests were conducted to establish the process parameters for a single pass coating i. e. , gas pressure and temperature, powder drum speed, nozzle traverse velocity, nozzle index and standoff. The process parameters as well as results of weight gain and coating thickness are presented for 90 wt. % Fe-10 wt. % MoC and 75 wt. % Fe-25 wt. % MoC, are presented in the Examples 1 and 2 below EXAMPLE 1 [00105] First mixture of 90 wt. % Fe-10 wt. % MoC was applied according to the above mentioned procedure in a mixture with Helium, with the following parameters.

Pressure: 300 psi, Temperature: 400°C, Powder Drum Speed: 3 rpm; Nozzle Traverse Velocity: 650 mm/sec; Nozzle Index : 1 mm; No. of Passes: 1 [00106] The results are reported on table I TABLE I Specimen No. Weight Gain (g) Coating Thickness (mils) 1. 1832 1 to 2 2. 1960 1 to 2 3. 1657 1 to 2 4. 1564 1 to 2 5. 1611 1 to2 6. 1676 0 to 2 7. 1719 0 to 2 8. 1915 0 to 1 9. 1562 1 to 2 10. 1666 1 to 2 11. 1840 0 to 1 12. 2006 2 to 3 13. 2018 1 to 2 [00107] As shown in Table 1 coating thickness of 1 to 2 mils 925 to 50 microns) was achieved for all samples. The weight gain indicates that the powders of this composition do not grit blast the Inconel substrates.

EXAMPLE 2 [00108] A second mixture of 75 wt% Fe-25 wt% MoC was applied according to the above mentioned procedure with Helium, with the following process parameters: Pressure: 300 psi-Temperature: 400°C-Powder Drum Speed: 3 rpm-Nozzle Traverse Velocity: 650 mm/sec-Nozzle Index : 1 mm-No. of Passes: 1 [00109] The results are reported in table 11 below TABLE 11 Specimen No. Weight Gain (g) Coating Thickness (mils) 14. 0573 1 to 2 15. 1111 0 to 1 16. 1114 0 to 2 17. 1101 Oto 1 18. 1078 1 to 2 19. 1134 Oto 1 20. 1361 1 to 2 21. 1283 Oto 1 22. 1331 1 to 2 23. 1304 1 to 2 24. 1217 0 to 1 25. 1331 1 to 2 [00110] As shown in Table II coating thickness 1 to 2 mils (25 to 50 microns) was achieved for all samples. The weight gain indicates that the powders of this composition do not grit blast the Inconel substrates.

[00111] With a 50 wt% Fe-50 wt% MoC mixture, a weight gain was achieved, but with a decrease in substrate thickness indicating that grit blasting of the Inconel substrate was taking place.

[00112] Since certain changes may be made in the above apparatus and methods without departing from the scope of the disclosure herein involved, it is intended that all matter contained in the above description, as shown in the accompanying drawing, shall be interpreted in an illustrative and not limiting sense. It is not intended that the disclosure be limited to the illustrative embodiments.

[00113] It should also be appreciated that for simplicity and clarity of illustration, elements shown in the Figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements are exaggerated relative to each other for clarity. Further, where considered appropriate, reference numerals have been repeated among the Figures to indicate corresponding elements.

[00114] In summary, a method of applying a catalyst to a substrate surface of a reactor chamber comprises applying to the substrate surface a mixture having particles of the catalyst, optionally particles of a ductile material, and a gas, at an application temperature and with an application kinetic energy, causing bonding of the particles to the substrate surface. The particles have a melting temperature and the application temperature is lower than the melting temperature of the particles. At least part of the particles mechanically deform upon application of the mixture at the application temperature and at the application kinetic energy. Application of the mixture having particles of the catalyst onto the substrate surface can be preceded by application of a first mixture comprising particles of a ductile material and gas. [00115] The present disclosure has been explained with reference to specific embodiments. Other embodiments will be apparent to those of ordinary skill in the art in view of the foregoing description. The scope of protection of the present disclosure is defined by the appended claims.