Background of The Invention

This invention relates generally to catalyst compounds and, more specifically to

the preparation and characterization of Cu-Al-O catalysts to replace Cu/Cr catalysts

in specific applications.

The commercial catalysts for hydrogenolysis of carbonyl groups in organic

compounds have been dominated by Adkins' catalyst since the 1930's (H. Adkins,

R. Connor, and K. Folkers, U.S. Patent No. 2,091,800 (1931)). The Adkins'

catalyst is a complex mixture of primarily copper oxide and copper chromite. The

catalyst is used in hydrogenolysis reactions, for example the catalytic

hydrogenolysis of an ester to alcohols, illustrated generally by the following

reaction:

_Rl C O R ₂ + 2H ₂ ► Ri C— OH ₊ R ₂ OH

Under reaction conditions it is believed that the catalyst reduces to a mixture of

metal copper, cuprous oxide and copper chromite. One of the crucial roles of

chrome in Cu/Cr catalysts is that it behaves as a structural promoter.

The Cu Cr catalysts have widespread commercial and industrial application in

such diverse processes as hydrogenation of aldehyde in oxoalcohol finishing,

hydration of acrylonitrile, fatty acid hydrogenolysis, hydrogenolysis of methyl

esters, reductive amination, and a myriad of other hydrogenation and oxidation

reactions such as are listed below. U.S. Patent No. 3,935,128, to Fein et al,

provides a process for producing a copper chromite catalyst. U.S. Patent No.

4,982,020 to Carduck et al., discloses a process for direct hydrogenation of

glyceride oils where the reaction is carried out over a catalyst containing copper,

chromium, barium and/or other transition metals in the form of oxides which, after

calcination, form the catalyst mass. U.S. Patent No. 4,450,245 to Adair et al.,

provides a catalyst support wherein the catalyst is employed in the low temperature

oxidation of carbon monoxide, another important application of such catalysts.

Environmental issues involving disposal of chrome-containing catalysts,

however, are expected to eventually eliminate their use in many countries.

Additionally, catalyst activity is one of the most important factors determining a

catalyst's performance. It is, therefore, advantageous to employ non-chrome,

copper-containing catalysts having good catalyst activity to replace currently used

Cu/Cr catalysts in hydrogenation, alkylation and other reactions.

Several prior art, non-chrome containing catalysts are known. For example,

U.S. Patent 5,418,201, to Roberts et al., discloses hydrogenation catalysts in

powdered form and method of preparing a hydrogenation catalysts comprising

oxides of copper, iron, aluminum and magnesium. U.S. Patent 5,243,095 also to

Roberts et al. provides for the use of such copper, iron, aluminum and magnesium

catalysts in hydrogenation conditions.

U.S. Patent No. 4,252,689 to Bunji Miya, describes a method of preparing a

copper-iron-alumina catalyst used in hydrogenation. U.S. Patent No. 4,278,567 to

Bunji Miya et al., discloses a similar process for making a copper-iron-aluminum

catalyst. U.S. Patent No. 4,551,444 to Fan-Nan Lin et al., provides a five-

component catalyst wherein the essential components are copper, an iron group

component, a component of elements 23-26, an alkali metal compound and a

precious metal compound.

C. W. Glankler, Nitrogen Derivatives (Secondary and Tertiary Amines,

Quarternary Salts, Diamines, Imidazolines), J. Am. Oil Chemists ' Soc, November

1979 (Vol 56), pages 802A-805A, shows that a copper-chromium catalyst is used to

retain coarbon to carbon unsaturation in the preparation of nitrogen derivatives.

U.S. Patent 4,977,123 to Maria Flytzani Stephanopoulos et al., discloses

extruded sorbent compositions having mixed oxide components of copper oxide,

iron oxide, and alumina. U.S. Patent 3,865,753, to Broecker et al, provides a

process for preparing a nickel magnesium aluminum catalyst used for the cracking

of hydrocarbons. The prior art, non-chrome containing catalysts have several

disadvantages that limit the industrial applicability ofthe catalysts.

An ideal catalyst should be both chemically and physically stable. Chemical

stability is demonstrated by consistent catalyst activity in an acceptable time period.

Physical stability is demonstrated by maintaining a stable particle size or physical

form during the chemical reaction. Moreover, an ideal catalyst would have narrow

particle distribution since particle size affects filtration speed in a commercial

process employing the catalysts. The stability is further demonstrated by resistance

to common poisons such as sulfur compounds, organic chlorines, bromine and

iodine compounds. Generally, stability is tested using Cu/Cr catalyst as the

standard catalyst.

An ideal catalyst also would have a low percentage of leachable cations. This

ensures the maintenance of catalyst activity and a good product quality.

Furthermore, it is important the catalyst function well in commercial

applications. For example, the hydration of acrylonitrile to acrylamide over a

copper-containing catalyst is an important industrial application. Several different

copper catalysts have been developed for this application, as indicated by the prior

art patents. The catalysts include copper/chrome, copper/silica, copper on

kieselguhr, Raney copper, ion exchange copper on silica and copper on alumina

catalysts. Most of the prior art catalysts used in this application have the problem

of deactivation. The catalyst is deactivated by the accumulation of polyacrylamide

on the surface or by the oxidation of surface copper. Selectivity is also important.

Normally, hydration of C-N bonds is favored by acidic oxides while hydrolysis of

C-C bonds is favored by basic oxides. Therefore, the surface acidity ofthe catalyst

is crucial to this application.

For some other applications that require some surface basicity, alkaline metal or

alkaline metal compounds should be remained or added to the catalyst matrix.

Summary of the Invention

It is among the principal objects of the present invention to provide a non-

chrome, copper-containing catalyst that can be employed as a catalyst in place of

Cu/Cr catalysts in new or conventional chemical reactions.

It is another object of the present invention to provide a non-chrome, copper-

containing catalyst that exhibits comparable or superior activity and selectivity to

conventional Cu/Cr catalysts in a numerous chemical reactions.

Another object of the present invention is to provide a non-chrome, copper-

containing catalyst having a spinel crystal structure analogous to the spinel crystal

structure of conventional Cu/Cr catalysts,

Still another object of the invention to provide a non-chrome, copper-

containing catalyst that contains an optimal ratio of copper to alumina.

Yet another object of the present invention is to provide a non-chrome, copper-

containing catalyst thereby eliminating the environmental issues associated with the

disposal of chrome-containing catalysts.

A still further object of the invention is to provide a non-chrome, copper-

containing catalyst that is relatively stable, and has a low percentage of leachable

cations.

Still another object ofthe present invention is to provide a non-chrome, copper-

containing catalyst that is efficient to prepare, functions well as a Cu/Cr catalyst in

new or conventional chemical reactions, has good selectivity and is not easily

deactivated.

In accordance with one aspect of the invention, a non-chrome, copper-based

catalyst, Cu-Al-O, and a method of preparing the same are provided wherein the

catalyst is prepared by co-precipitation from a solution consisting essentially of a

soluble copper salt and a soluble aluminum compound in the presence of a

precipitating agent. The copper salt is illustratively cupric nitrate, Cu(N0 ₃ ) ₂ and

the aluminum compound is preferably a basic aluminum salt, most preferably an

aluminate such as sodium aluminate, Na ₂ Al ₂ 0 ₄ . The copper salt and the aluminum

compound are preferably dissolved separately and the solutions are slowly mixed in

an aqueous precipitation mixture in approximately 5 minutes to 12 hours, more

preferably in approximately 0.5 to 2 hours. The precipitant is preferably added to

the precipitation mixture to maintain a pH of about 6.5 to 8.5, most preferably 7.4 ±

0.5. The precipitant is illustratively sodium carbonate, Na ₂ C0 ₃ . The precipitate is

filtered, washed to removed excess sodium, and dried, preferably at a temperature

of from room temperature to about 150°C, most preferably between about 100°C

and 150°C. The dried product is then calcined at a temperature ranging from about

300°C to about 1000°C, the temperature of calcining being chosen to give the

catalyst desired properties. The dried product , to be used in a powder form, is

calcined at a preferred temperature of approximately 700°C to 900°C for

approximately 0.5 to 4 hours. The dry powder, to be extrudated, after drying is then

mixed with water to a desired water content. The dry powder, to be tableted, is

calcined at a temperature of approximately 400° to 700°C.

The preferred catalysts of the present invention are generally homogeneous

compositions having an aluminum content expressed as Al ₂ O ₃ greater than about

20% by weight, preferably about 25% to about 70% by weight, and more preferably

about 30% to about 60%. The copper content expressed as CuO is les than about

80% by weight, preferably about 40% to about 70% by weight. This convention is

used throughout this patent, unless noted otherwise. The catalysts are generally

homogeneous, rather than being supported by a heterologous matrix. The catalysts

show a spinel structure when calcined above about 700°C. Although the catalysts

calcined at lower temperatures show no x-ray diffraction patterns characteristic of a

spinel, and although they have different characteristics, such as higher leachable

cations, they nonetheless show remarkable catalytic activity and selectivity in

numerous reactions.

The Cu-Al-O catalyst produced by the method of the invention has been found

to be comparable with or favorable to commercial Cu/Cr catalysts widely used in

numerous hydrogenation and hydrogenolysis reactions, in terms of the most

important characteristics of a commercial catalyst. In many reactions it has been

found to have a far greater activity than commercially available Cu/Cr catalysts,

and a remarkable selectivity. In extruded or tableted form, they have high side

crush strength. They have high pore volumes, typically exceeding 0.25 ml/g . The

powder form catalyst has high filtration rates. They resist poisoning. They have

low cation extractability.

The solid catalyst formed as an extrudate ofthe catalyst ofthe present invention

is preferably formed from a Cu-Al-O powder with LOD of thirty to fifty percent,

the extrudate being formed with and without binder or lubricant. The extrudate has

a pore volume of approximately 0.15 ml/mg to approximately 0.7 ml/g, preferably

greater than 0.3 ml/g. The extrudate has a bulk density of approximately 0.6 g/ml

to approximately 1.0 g/ml and a surface area of from 15 m ² /g to 250 m ² /g. The

preferred extrudate has a bimodal pore size distribution centering around 100 A and

around 1000 A to 2000 A.

When formed as a tablet, the catalyst has a pore volume greater than about 0.25

ml/g and a bulk density of approximately 0.8 g/ml to approximately 1.5 g/ml.

The activity of the Cu-Al-O catalysts of the present invention can be increased

in hydrogenolysis and other applications by the addition of promoters such as Ce,

Mn, Ba, Zn, Co, and Ni compounds in amounts less than 50% by weight, preferably

less than 25% by weight. In some applications the promoter is preferably less than

5% by weight, and most preferably between 0.1% and 2.5% by weight. The

presence of alkaline metal compounds will improve selectivity in some

applications.

Brief Description of the Drawings

Fig. 1 illustrates the x-ray diffraction of the Cu-Al-O catalyst calcined at

600°C;

Fig. 2 illustrates the x-ray diffraction of the Cu-Al-O catalyst calcined at

800°C;

Fig. 3 illustrates the thermal gravimetric analysis (TGA) of the Cu-Al-O

catalysts in hydrogen atmosphere;

Fig. 4 is a graph illustrating particle size distribution ofthe Cu-Al-O catalyst of

the present invention as a function of precipitation time;

Fig. 5 illustrates the thermal gravimetric analysis (TGA) in hydrogen of the

Cu-Al-O catalysts at different numbers of washings;

Fig. 6 is a graph illustrating pore size distribution of catalyst tablets having

different densities;

Fig. 7 is a graph illustrating cumulative and incremental pore volume of 3/16

inch by 3/16 inch catalyst tablets;

Fig. 8 is a graph illustrating incremental pore size distribution of a 1/16 inch

catalyst extrudate;

Fig. 9 is a graph illustrating the effect of sodium content of the Cu-Al-O

catalyst of the present invention on catalyst activity; and letters A through F

represent catalyst ID #011 through #016.

Detailed Description ofthe Invention

The present invention contemplates a catalyst, Cu-Al-O, the method of

preparing the Cu-Al-O catalyst by the co-precipitation of copper nitrate and sodium

aluminate using soda ash (sodium carbonate) as a precipitant, and applications

employing the Cu-Al-O catalyst. The preparation of the catalyst is best illustrated

by the following examples:

PREPARATION OF CU-AT.-O CATAT .VST

Example 1

The Cu-Al-O catalyst ofthe present invention was prepared as follows:

Weigh out 1640 g of copper nitrate solution (15.48% Cu) and dilute with

deionized water to 2500 ml. Weigh out 815.6 g sodium aluminate (25% A1 ₂ 0 ₃ ) and

dilute with deionized water to 2500 ml. Add 2500 ml deionized water to a 12 liter

tank. Weigh out 318 g sodium carbonate (soda ash) and dissolve in deionized water

to 1500 ml. Simultaneously add the copper nitrate solution and sodium aluminate

solution to the 2500 ml of deionized water. The copper nitrate and sodium

aluminate solutions may be added at a rate of 33 ml per minute. Add the sodium

carbonate (soda ash) solution to the mixture, keeping the slurry at a constant pH

ranging from approximately 6.0 to 8.5, preferably about 7.4, by adjusting the rate of

addition of the soda ash solution. The precipitation can be carried out at a wide

range of temperatures from room temperature to 90°C or more. Typically the

precipitation is carried out at room temperature. Filter the slurry to form a filter

cake. Wash the filter cake with 3000 ml of deionized water three or more

(preferably four ) times. Dry the .filter cake at 120° C overnight. Calcine the dried

Cu-Al-O powder at 400°C for two hours. Do the following testing and

characterization on this calcined powder: particle size distribution, acetic acid

soluble cations, surface area, x-ray diffraction (XRD), thermal gravimetric analysis

(TGA) and hydrogenolysis of coconut fatty acid activity test.

Examples 2-7

The following examples 2-8 were carried out in the same manner as example 1,

except that the dried Cu-Al-O powder was calcined for two hours in air at the

temperatures given below:

Example 2 500°C.

Example 3 600°C

Example 4 700°C

Example 5 800°C

Example 6 900°C

Example 7 1000°C

CHARACTERIZATION OF Cu-Al-O CATALYST PREPARED BY EXAMPLES 1 -7

Example 8 Leachable Catalyst Cations

The leachable cations measurements are performed by reacting 100 ml 10%

acetic acid with 10 g of powder catalyst for one hour with continuous stirring. The

solution is separated, filtered and washed. The cation content in the solution is

quantitatively analyzed.

The following Table 1 illustrates the leachable copper (Cu) and aluminum (Al)

in catalyst prepared at different calcination temperatures. A commercially available

Cu/Cr catalyst was also tested for comparison.

Table 1 Effect of Calcination Temperatures on Cu-Al-O Catalysts Properties

Ex. Catalyst Calcination Particle Size Cu%, Al%, Surface

No. ID Temp. °C micron leachable leachable Area, m ² /g v, dv, dv, 10% 50% 90%

Cu/Cr 001 1.8 15.7 62.6 4.3 0.7(Cr) 26 Control

1 002 400 3.5 1 1.5 29.7 27 3.27 188

2 003 500 3.3 10.4 25.3 37.1 13.1 167

3 004 600 3.5 10.3 22.7 6.9 4.00 1 14

4 005 700 2.7 8.9 28.3 3.9 1.90 73

5 006 800 2.1 8.7 22 2.3 0.58 39

6 007 900 1.7 6.8 21.1 2.0 0.33 14

7 008 1000 1.3 5.5 26.8 0.77 0.10 7

As illustrated in the above table, if the catalyst is calcined at 400° (Example 1),

the leachable Cu is 27%. The leachable Cu dropped to <5% if the catalyst is

calcined at a temperature higher than 700°C (Example 5-7). Therefore, the

leachable Cu content can be controlled by calcination temperature.

Example 9

Characterization ofthe Cu-Al-O Catalysts bv X-Rav Diffraction (XRD)

Figs. 1 and 2 are XRD analyses of the Cu-Al-O catalysts of the present

invention calcined at different temperatures. XRD analysis results illustrate that the

catalysts are nearly amoφhous when calcined at temperatures below 500°C

(Examples 1-2). Fig. 1 shows that At 600°C (Example 3), the diffraction pattern

corresponding to CuO phase appears. At this temperature, CuO is the only

crystalline phase detected.

As shown in Fig. 2, when calcination temperatures are increased to 700° or

800°C (Examples 4-5), in addition to CuO formation, a new spinel crystalline phase

corresponding to copper aluminate (CuAl ₂ 0 ₄ ) appears. By comparing the XRD

data with the results of Table 1 and Table 17, it can be seen that the formation of

crystalline CuO and CuAl ₂ 0 ₄ in the Cu-Al-O catalyst not only decreases the

catalyst leachable cations, but also increases catalyst activity.

Example 10

Characterization ofthe Cu-Al-O Catalyst bv Thermal Gravimetric Analysis (TGA)

A series of laboratory prepared Cu-Al-O catalysts of the present invention

calcined at different temperatures were characterized by thermal gravimetric

analysis (TGA). TGA experiments were run under both hydrogen and nitrogen

atmospheres. As stated above, copper aluminate spinel crystal phase, as well as

cupric oxide (CuO) phase, appear as calcination temperatures increase to >700°C.

TGA results, as shown in Fig. 3, illustrate that there are two stages of weight loss if

the catalyst was calcined at higher than 700°C. The first weight loss occurred at

approximately 150° to 200°C, depending upon the calcination temperature. By

correlating the results with the XRD measurement results, as discussed above, the

weight lost in this temperature range corresponds to the reduction of cupric oxide.

The second weight loss occurred at 350° to 400°C and corresponds to the reduction

of copper aluminate. The second weight loss only occurred with catalysts calcined

at 700°C or higher temperatures.

As the calcination temperature increases the percentage of weight loss from the

first weight loss ( 150°C to 200°C) decreases while the percentage of weight loss

from the second weight loss (350°C to 400°C) increases. It will be noted that the

percentage of weight loss at each of the two weight loss stages are approximately

the same for catalyst calcined at 900° (Example 6) and 1000°C (Example 7). That

is, the copper content of the CuO and CuAl ₂ 0 are about the same. The fingeφrint

characteristics of the TGA in H ₂ , as illustrated in Fig. 3, provide a convenient and

reliable method for identifying and quantifying the formation of spinel copper

aluminate.

Example 1 1

Particle Size and Surface Area

Figure 4 illustrates the precipitate particle size at different time periods in

Example 1. It should be noted that the particle size becomes larger as the

precipitation time goes on in the first hour of the precipitation procedure described

in Example 1. The particle size remains constant after the first hour. Therefore, at

a constant temperature, pH value and agitation speed, the precipitate particle size

can be controlled by adjusting the slurry concentration.

As illustrated in Table 1 above, the particle size decreased marginally as the

calcination temperature increased. The particle size, however, is within the range

of commercial Cu/Cr catalysts.

It should be noted, however, that the surface area shrank more than 25 times

from 188 m ² /g to 7 m ² /g as the calcination temperature increased from 400°C

(Example 1, Table 1) to 900°C (Example 6, Table 1) while the catalytic activity

remained almost the same, as will be explained in greater detail below. The

decrease in surface area without a loss in catalyst activity suggests that most of the

surface area is in micro-pores and is inaccessible by large reactant molecules such

as fatty acids or ester.

Example 12 Thirty r30 > Gallon Scale-Up

The Cu-Al-O catalyst preparation, as provided in Example 1, was scaled-up to a

30 gallon tank. The particle size distribution and surface area are similar to the

small scale preparation. The particle size distribution versus precipitation time of

catalyst ID # 009 is illustrated below in Table 2.

Table 2

Particle Size Distribution of 30 Gallon Precipitation

(Catalyst ID #009)

Time (min.) D-10% D-50% D-90%

10 3.0 8.3 19.9

20 3.3 9.1 22.8

30 3.9 9.9 23.0

40 3.9 9.5 21.2

50 4.2 10.4 23.3

60 4.1 10.4 24.9

70 4.2 10.2 24.3

83 4.1 10.2 25.3

Other chemical and physical properties of the 30 gallon scale-up are compared

to the laboratory preparation. To compare the results, the 30 gallon scale-up

prepared powder was calcined at 800°C (catalyst ID #10) for surface area and

leachable Cu and Al analyses. The comparisons are illustrated below in Table 3.

Table 3

Comparison of Some Chemical/Physical Properties of Cu-Al-O

Catalysts From 30 Gallon, Pilot Plant Tank with Lab Preparation

Example 12 Example 5 Example 13

Scale 30 gallon Lab Pilot Plant

Leachable Cu, % 1.84 2.17 1.67

Leachable, Al, % 0.47 L_ 0.6 0.54

Leachable Na, 377 200 50 ppm

Surface Area, m ² /g 31 35 27

LOI, (950 °C) 0.95 1.95 1.0

D-10%, μm 5.5 4.1 4.3

D-50%, μm 13.9 10.3 10.7

D-90%, μm 29.8 25.1 21.8

As shown in Table 3, the leachable copper is less than 2% and the leachable

aluminum is less than 1%.

Example 13 Pilot Plant Scale-Up Trial

The catalyst of the present invention was made on a larger scale and the

chemical and physical properties were analyzed. The scale up factor is 190 times of

Example 1. The analytical results of powder made from the pilot plant scale-up

also is listed in Table 3, above. As shown in Table 3, the catalyst calcined at 800°C

had particle size distributions of D-10% 4.3 μm, D-50% 10.7 μm, and D-90% 21.8

μm. These distributions are approximately the same values as found in the

laboratory preparation. Furthermore, the surface area, leachable cations and loss on

ignition (LOI) are similar to the lab preparations. The calcined powder particle size

and distribution ofthe Example 13 are similar to Example 5.

Precipitation Variables

The effects of mixing speed and feed pump rate on particle size were studied.

Example 14

Mixing Speed:

Two mixing speeds, 410 φm and 710 φm were tested. Preliminary lab results,

shown below in Table 4, indicate that mixing speed does not dramatically affect

precipitate particle size distribution. However, high mixing speed, e.g. 710 φm,

gives smaller particle size.

Table 4 Effects of Mixing Speed (RPM) on Slurry Particle Size

RPM D-10% D-50% D-90%

410 3.9 13.4 35.2

714 3.6 10.1 21.42

Example 15

Feed Pump Rate;

The effects of the copper and aluminum solution feed pump rates on the

particle size were studied. The precipitation details are the same as Example 1, the

differences in this series of experiments are their feed pump rates. As shown in

Table 5, rate at which the copper and aluminum solutions are fed into the

precipitation does not appear to affect slurry particle size.

Table 5 Effects of Feed Pump Speed on Slurry Particle Size Distribution

Feed Pump D-10% D-50% D-90% Rate, ml/min

15.2 3.8 11.1 25.6

26.3 3.6 10.1 21.4

55 3.5 9.3 20.4

73 3.8 10.5 28.7

As shown by the above data, the slurry particle size remains almost constant as

the feed pump rates increased from 15 ml/min to 73 ml/min.

Example 16 Effects of Sodium Content on Catalyst Properties

Table 6, below, illustrates the chemical and physical properties of the Cu-Al-O

catalyst of the present invention with different sodium content. The precipitation

details are the same as Example 1 , except the washing. All of these catalyst were

calcined at 800°C for 2 hours.

Table 6

Physical/Chemical Properties of Cu-AI-O Catalysts with Different Sodium Content

Catalyst 011 012 013 014 015 016 LD. #

CuO% 51.7 55.8 58.3 58.0 59.6 58.5

A1_0 ₃ % 32.8 35.4 37.3 37.9 37.5 37.37

Na,0% 5.26 2.70 1.29 0.36 0.09 0.02

LOI % 3.72 3.86 2.72 1.98 2.35 1.95 (950 °C),

Leachable 2.04 8.80 7.89 2.32 2.30 2.17 Cu, %

Leachable 4.05 2.41 1.42 0.72 0.76 0.60 AI, %

S. A. 24 44 48 42.7 41.5 35 mVg

All the catalysts were prepared from the same batch. Catalyst ID# Oi l is a

catalyst prepared without washing. Catalysts ID#'s 012 through 016 are catalysts

prepared with one, two, three , four and five washes respectively. Each wash uses

3000 ml distilled water. Table 6 above showed that the preferred number of

washings, i.e. four, reduces the Na ₂ 0 content to <1% in the catalyst.

Generally speaking, the lower the sodium content, the lower the cation

leachability will be. However, the leachable Cu in catalysts ID# 011 is

unexpectedly low, e.g. 2.04, as is the surface area, e.g. 24. There is not a clear

relationship between the surface area and sodium content.

As stated above, Example 10, TGA in H ₂ can be used as a quick method for

identifying the spinel structure formation in the Cu-Al-O catalyst. The weight lost

in the region of 150° to 200°C is the reduction of CuO and the weight lost in the

region of 350° to 400°C corresponds to the reduction of spinel copper aluminate. A

series of five Cu-Al-O catalysts, all calcined at 800°C, each having a different

sodium content were characterized by TGA in hydrogen. For simplicity, the results

from only three ofthe catalysts were shown in Fig. 5.

Curves A. B and C are the hydrogen reduction profiles of catalysts washed one,

two and three times respectively to remove sodium. As illustrated, curves A, B and

C have different profiles when heated in hydrogen. As shown in curve A there is

almost no weight loss corresponding to reduction of spinel copper aluminate.

Further, the reduction temperature for CuO was shifted to a higher temperature.

Curve B indicates that the reduction of copper aluminate appears at approximately

350° to 400°C and the reduction temperature for the CuO is lower than curve A.

Curve C represents the catalyst washed three times. The weight loss of this catalyst

corresponding to the reduction of copper aluminate was further increased and the

CuO reduction temperature was decreased. This indicates that residual sodium in

the catalyst not only retards copper aluminate formation, but also increases CuO

reduction temperature.

Example 17 Effects of Cupric Oxide (CuO ^{^} l Content on Filtration Speed

One of the important characteristics of powder catalysts is their filterability.

The Cu-Al-O catalyst of the present invention typically contains ~ 60% CuO. A

series of catalysts with different CuO loadings were prepared. All of the catalysts

were tested for filterability. The initial results indicated that the catalyst particle

sizes have wider distribution as the CuO content increases. The wider distribution

basically is caused by an increase in the number of smaller particles. Therefore,

filtration speed decreases as the particles size distribution broadens.

Table 7 shows the filtration speed test of Cu-Al-O catalysts of the present

invention along with commercially available Cu/Al or Cu/Cr catalysts, # 017 and #

001. The filtration speed tests were performed by t ^f ollowing procedures: 15 g of

powder catalyst was dispersed in 100 ml deioniz water by stirring 5 minutes.

Filtration speed was tested under 18 inches vacuum with 5.5 cm diameter #42

Whatman filter paper. The time in Table 7 was recorded when solid first appeared

in the funnel.

Table 7

Filtration Speed Test of Cu-Al-O Catalyst

Catalyst Catalyst CuO, Vacuum, Time,

# Component % inch

018 CuO,Al ₂ 0 ₃ 61% 18 2'37"

019 CuO,Al ₂ 0 ₃ 70% 18 4'39"

020 CuO,Al ₂ 0 ₃ 80% 18 6' 17"

017* CuO,Al ₂ 0 ₃ -82% 18.5 35'

001 * CuO,Cr ₂ 0 ₃ -47% 18 4'53"

^♦ commercially prepared catalysts

The results, as illustrated in Table 7, indicate that filtration speed of the Cu-Al-

O catalyst of the present invention is comparable to Cu/Cr catalyst # 001. More

importantly, it should be noted that the Cu-Al-O catalyst # 020 and the commercial

Cu-Al-O # 017 have similar composition but the filtration speed of the catalyst

prepared by the method ofthe present invention can be filtered five (5) times faster

than the commercially prepared catalyst (# 017).

PREPARATION OF CATALYST TABLETS AND F.XTRT JDATES

Example 1 Cu-Al-O Catalyst Tablets

Catalyst powders for tablet formation were prepared according to Example 1

with different calcination temperatures ranging from 300° to 800°C. The

calcination temperatures and Scott densities of each sample of calcined powders are

listed below in Table 8.

Table 8 Properties of the Powders for Slugging

Powder I.D. # Calcination Temp. Scott Density, g/ml °C

021 300 0.26

022 500 0.26

023 600 0.34

024 700 0.32

025 800 0.32

Tablets were made from the powders after the powder was mixed with 5%

graphite powder, slugged and granulated. Powder #025 had good flow

characteristics. The tablets made from Powder #025 had a good overall appearance.

However, the side crush strength was only approximately 3 to 4 pounds for 1/8" by

1/8" tablet.

The tablets may be formed in numerous standard sizes, such as 1/8" by 1/8",

3/16" by 3/16", 1/4" by 1/4", 3/16" by 1/4", or 1/4" by 1/16", as is known in the art.

Tablets also were made from Powder # 022. Four 1/8 inch by 1/8 inch sample

of tablets, T-l, T-2, T-3 and T-4 were made from powder #022 and were tested for

their physical properties (Table 9). The results of these test are included in Table 9:

Table 9 The Physical Properties of 1/8" X 1/8" Tablets

Tablet # T-l T-2 T-3 T-4

Side crush 26.9 14.4 12.3 15.4 Strength lb

Packed Bulk 1.08 1.00 0.91 0.93 Density, g/ml

Pore Volume, 0.39 0.43 0.49 0.45 ml/g

Pill weight, g 0.046 0.044 0.039 0.048

Length, in 0.130 0.132 0.131 0.151

Diameter, in 0.125 0.125 0.125 0.125

Pill Density, 1.77 1.69 1.50 1.85 g/ml

Pill Feed 0.529 0.529 0.529 0.494 Scott Density, g/ml

Graphite 5% 5% 5% 2% Powder

It should be noted that the side crush strength was relatively high, e.g. from

12.3 lb. to 26.9 lb. while the bulk density is relatively low, e.g. from 0.91 g/ml to

1.08 g ml.

Example 19 Effects of Tablet Density on Pore Size Distribution

The relationship between bulk density and crush strength was investigated. The

goal was to obtain an acceptable crush strength with a lower bulk density.

Furthermore, the effect of tablet density on pore size distribution was investigated.

The Hg pore size distribution of Tablet T-l and Tablet T-3 are shown in Fig. 6.

It is clear from Fig. 6 that the tablet density has a strong effect on the pore size

distribution in the range of 900 A to 1100 A. The difference in total pore volume

between Tablet T-l and Tablet T-3 is due to the difference in pore volume at this

region (900 A to 1100 A). There is no obvious effects of tablet density on the pore

size smaller than 900 A.

Example 20 Effects of Different Tablet Size on the Physical Properties

Two different size tablets were made from powder catalyst ID # 023. As

shown in Table 8, catalysts ID # 023 was calcined at 600°C and had a Scott density

of 0.34 g/ml. The tablets were given catalyst identification numbers of T-5 and T-

6. The physical properties ofthe tablets are illustrated in Table 10.

Table 10 Some of Physical Properties of the Different Tablet Size

Tablet ID # T-5 T-6

Tablet Size, inch x inch 3/16X3/16 3/16X1/8

Length, in. 0.194 0.134

Diameter, in. 0.189 0.190

Weight, g. 0.144 0.109

Pill Density, g/ml 1.60 1.73

Side Crush Strength, lb 23.7 31.7

Bulk Density, g/ml 0.989 1.13

Pore Volume, ml/g 0.41 0.34

As can be appreciated from Table 10, the tablets have a good side crush

strength ( > 20 lb.) while the bulk density (B.D.) remains relatively low, 0.989 g/ml

and 1.13 g/ml. and the pore volume (>0.34 ml/g) remains relatively high.

Example 21 Effect of Tablet Density on Tablet Physical Properties

The effect of tablet density on other physical properties was studied in 1/8 inch

by 1/8 inch tablets. All of the tablet feeds were made from the same batch of

catalyst powder. The powder was calcined at 600°C for 4 hours. Two groups of

tablets were made, each group having a different graphite content. The first group,

containing catalyst tablet identified at ID#'s T-7, T-8 and T-9 contained 2%

graphite. The second group, containing catalyst tablets ID#'s T- 10, T-l 1 and T-l 2

contained 1% graphite. Table 1 1 illustrates some of the physical properties of the

tablets.

Table 11 Some of the Physical Properties of the Tablets

As shown, the crush strength increases dramatically with tablet density. Since

there is a correlation between crush strength and tablet density, and if all the other

factors are equal, the targeted crush strength can be reached by selecting the

appropriate tablet density. It can be seen from Table 12 that a target pore volume

can be obtained by controlling tablet density.

Furthermore, four different densities of 3/16 inch by 3/16 inch tablets were

made. These four tablets were designated by ID#'s T-13, T-14, T-15 and T-16.

The physical properties ofthe four tablets are shown in Table 12.

Table 12 Physical properties of 3/16"X3/16" Cu-Al-O Tablets

As best illustrated in Fig. 7, catalyst density only affects macro-pore volume,

i.e. pore diameter from 0.07 micron to 0.3 micron (700 A to 3000 A), with almost

no effect on pore sizes small that 0.02 micron (200 A).

Example 22 Cu-Al-O Catalyst Extrudate

A series of 1/16 inch Cu-Al-O extrudates were prepared from different powder

feeds. LOD (Loss on Drying) of these powder feeds having from 35% to 42.5%.

The extrudates were dried at 120° C overnight followed by calcination at 500°C for

3 hours. The basic physical properties ofthe samples are listed in Table 13.

Table 13

Physical and Chemical Properties of Cu-Al-O

1/16" Extrudate

Normally monovalent acids, such as HCl, HN0 ₃ , acetic acid or formic acid are

used for controlling rheology. Organic acids are preferred because of no chloride

corrosion and no NO _x emission when the acid decomposes.

In this invention, the extrudate samples were prepared without using any binder

or peptizer. The samples were prepared directly from dried powder with

LOD=40%. After calcination at 500°C, the average crush strength is above 5 lb.

The final extrudate pore volume and pore size can be controlled by mulling time.

As shown in Fig. 8, the prepared sample has bimodal pore size distribution centered

at -100 A and 1500 A and has a pore volume and pore size distribution similar to

the 1/8 inch tablet form.

APPT.TCATTONS USING THF. Cu-Al-O CATALYST OF THE PRESENT TNVFNTTON

Example 23 Qxoalcoh.pl Finishing

The oxoalcohol finishing activities of tablets ID #'s T-l and T-3 were tested

side by side with commercial Cu/Cr catalyst ID # T-l 7. The physical properties of

T-l and T-3 are listed in Table 9, above. Tablet T-3 has the same chemical

composition as T-l . However, there is a difference in their bulk densities, pore

volume and pore size distribution. The packed bulk density of commercial Cu/Cr

catalyst T-l 7 is approximately 1.52 times that ofthe tested Cu-Al-O catalysts ofthe

present invention and T-l 7 has approximately 26% more CuO. The primary test

results are shown in Table 14.

Table 14

Oxoalcohol Activity Test of 1/8" X 1/8" Cu-Al-O Tablets vs. Commercial Catalyst 1/8" x 1/8" Cu/Cr Tablet

Catalyst: T-l, 40 ml, B.D. = 1.05 g/ml, 42g catalyst contained 20.43 g CuO.

Carbonyl Conv, % 80

Acid Conv., % 34

Ester Conv., % 51

Catalyst: T-3, 40 ml, B.D. =0.91 g/ml, 35.85 g catalyst, contained 16.95 g CuO

Carbonyl Conv. % 84

Acid, Conv., % 50

Ester Conv., % 58

Catalyst: T-17 1/8" tablet, 40 ml. B.D. = 1.594 g/ml, 63.76 g catalyst, contained 25.74 g CuO.

Carbonyl Conv, % 85

Acid Conv., % 37

Ester Conv., % 51

Reaction conditions: H? flow rate = 18( ) scc/min. P= 1 150 psig.

LHSV = 2.2 hr', water = 1.15%, T= 128°C. Time on stream - 180 hours.

Table 14 shows that after 180 hours test, T-3 has similar activity with

commercial Cu/Cr catalyst T-l 7, but T-l has 5% lower conversion on carbonyl

conversion. However, for more porous table catalyst, T-3 of this invention, Table

14 clearly shows that T-3 has a higher activity than T-l 7 and T-l . Ester and acid

conversion are significantly greater than T-l 7. Further, the results indicated that

under given reaction conditions, oxoalcohol finishing reaction on catalyst T-l is

diffusion limited.

To better compare the novel Cu-Al-O catalyst with commercial catalyst in

oxoalcohol finishing, catalyst powder ID # 022 was made into tablets (ID # T-l 8)

of a similar size (3/16 inch by 3/16 inch) to a commercial Cu/Cr catalyst, T-l 9.

These catalysts were pre-reduced and stabilized in isodecyl alcohol (TRL). The

catalyst activity was tested compared to commercial Cu/Cr catalyst designated as T-

19. The results are shown in Table 15.

Table 15

Oxoalcohol Activity Test* of 3/16"X3/16"

Cu-Al-O TRL** vs. Cu/Cr TRL T-l 9

Catalyst: T-l 8, 3/16" TRL, 70.72 g/60 ml

HOS, hr 19 43 69.3 91

Carbonyl Conv, % 84.4 85.8 84.7 83.5

Acid Conv., % 41.8 41.0 54.8 54.1

Ester Conv., % 62.6 61.7 61.4 60.3

Catalyst: T-l 9 -3/16" TRL, 106.11 g/60 ml,

HOS, hr 19 43 69.3 91

Carbonyl Conv. % 86.9 88.9 87.0 86.2

Acid, Conv., % 33.3 38.9 49.3 49.4

Ester Conv., % 60.7 63.9 63.6 62.0

* Reaction conditions: H ₂ follow rate = 180 scc/min. LHSV 1.5 hr ^'1 , 1.15% H ₂ 0, T= 152° C, P= 1200 psig. ** TRL — catalyst reduced and stabilized in isodecyl alcohol.

The catalyst activities were tested for four days. The results shown in Table 15

indicate that the activities for acid and ester conversion are not significantly

different between the two catalysts. The tests show that the catalyst activity for the

novel Cu-Al-O catalyst in oxoalcohol finishing is approximately equivalent to that

of commercial chromium containing catalyst. However, the Cu-Al-O catalyst is

free of environmentally toxic chromium. The Cu-Al-O catalyst has a much lower

bulk density than the Cr/Cu catalyst and, therefore, weighs 1/2 to 2/3 of the

commercial available Cr/Cu catalyst.

Examples 24-28

Hydrogenolysis of Coconut Fattv Acid (CFA)

The following Examples, 24-30, describe the application of Cu-Al-O catalysts

of present invention to the hydrogenolysis of coconut fatty acid.

Example 24

Effects of Calcination Temperature

Table 16 illustrates the catalytic activity of various Cu-Al-O catalysts of the

present invention calcined at different temperatures. Catalyst ID# 001 is the

standard commercially available Cu/Cr catalyst.

The catalyst samples prepared from Example 1 to Example 7 are tested for the

activity and selectivity of hydrogenolysis of coconut fatty acid to fatty alcohol.

Table 16 Effects of Calcination Temperatures on Cu-Al-O Catalysts Activity

Example Catalyst Calcination Relative Selectivity*** Number ID# Temp* °C Activity** %

Cu/Cr Standard 001 440 100 0.11-0.18

1 002 400 155 0.13

2 003 500 198

3 004 600 152

4 005 700 151 0.17

5 006 800 177 0.1 1

6 007 900 127 0.12

7 008 1000 62 0.25

All catalysts wer e calcinec in air.

** The relative activity is calculated by the ratio of rate constant ofthe catalyst with that ofthe standard Cu/Cr catalyst. The rate constants are measured in the reaction time from 5 minutes to 120 minutes with the assumption of 90% conversion under the equilibrium conditions.

*** Selectivity is defined as weight percent of dodecane at 1.5% ester remaining in the reactor.

As shown in Table 16, catalytic activity in hydrogenolysis of coconut fatty

acids improved when the catalysts were calcined at higher temperatures. If the

calcination temperature exceeds 800°C, the catalyst begins to lose activity. This

apparently is due to the decomposition of cupric oxide and the spinel structure of

CuAl ₂ 0 ₄ in the catalyst. It will be appreciated that CuO is unstable at temperatures

greater than 800°C and it decomposes to Cu ₂ 0 and 0 ₂ A similar phenomenon was

observed for CuAl ₂ 0 ₄ . In Ar atmosphere and at 870°C, the following reaction takes

place:

4 CuAl ₂ 0 ₄ ^■ _► 4 CuA10 ₂ + 2 Al ₂ 0 ₃ +0 ₂

It is of interest to note that catalyst ID # 003, which was calcined at 500°C, had

a relative activity of 198% for hydrogenolysis of coconut fatty acid as compared to

the standard, catalyst ID # 001. As seen, there are two calcination temperature

ranges corresponding to greater catalytic activity. The high catalytic activity of the

catalyst calcined at 500°C, Example # 2 may be explained. Example # 2 (catalyst

ID # 003), as shown in Table 1, had a higher percentage of leachable copper. The

unusually high activity of that catalyst may be due to soluble copper in the reaction

slurry. It is further noted from Table 16 that the catalyst activity was maximized

where the catalyst was calcined at approximately 800°C and decreased as the

temperature increased beyond 800°C.

One of the concerns of hydrogenolysis of coconut fatty acid is the selectivity.

Table 16 shows that when Cu-Al-O catalyst of this invention is calcined at from

400°C to 800°C, the selectivity for this reaction is equal or better than the standard

commercial Cu/Cr catalyst.

Example 25

Effects of Catalyst Promoters

Cerium oxide (Ce ₂ 0 ₃ ) was tested as a promoter for the Cu-Al-O catalyst.

Table 17 shows the catalytic activity of a series of catalysts with different doping

amounts of Ce ₂ 0 ₃ It should be noted that the selectivity of the Cu-Al-O catalyst for

hydrogenolysis of coconut fatty acid is expressed as dodecane made at 1.5% ester

remaining.

Table 17 Effects of Ce ₂ 0 ₃ on the Catalytic Activity and Selectivity of Cu-Al-O

Catalyst Ce ₂ 0 ₃ Calcination S. A. Relative Selectivity ID # * % Temp °C** mVg Activity % ***

***

001 0 440 26 100 0.12-0.2

3

005 0 700 73 151 0.17

026 10 700 50 159 0.1 1

027 5 700 51 165 0.1 1

028 2.5 700 55 164 0.09

029 2.5 700 55 172 0.1 1

* Catalysts number 026, 027 and 028 were prepared by impregnation method.

Catalyst # 6 was prepared by co-precipitation method. **A11 catalysts were calcined in air. ** ""Calculation method is the same as shown in Table 16.

Table 17 shows that Ce ₂ 0 ₃ is an activity and selectivity promoter for fatty

acid/ester hydrogenolysis when used with the Cu-Al-O catalyst in this invention.

Further, it appears from the data that a 2.5% Ce ₂ O ₃ doped catalyst gives a better

activity and selectivity than 10% Ce ₂ 0 ₃ MnO. BaO and Ni promoted Cu-Al-O

catalysts in this invention have similar effects on the catalyst activity and

selectivity.

Example 26

Effect of Cupric Oxide Content ofthe Cu-Al-O Catalyst on Hvdrogenolvsis Activity

A series of catalysts with different cupric oxide (CuO) content were tested for

coconut fatty acid hydrogenolysis. The results are shown in Table 18.

Catalyst ID #031 gives the highest activity, 177% of the standard Cu/Cr

catalyst #001. As the CuO content increases, the activity for CFA conversion

drops. However, Table 18 shows that CuO content from 40% to 80% in the Cu-Al-

O catalysts in this invention exhibits higher or equal (Catalyst ID #033) activity to

the catalyst ID # 001, the standard Cu/Cr catalyst.

Table 18 Effects of CuO content on CFA Activity

Catalyst Catalyst CuO, % CFA Activity, % ID # Component LOI Free of E-118

030 CuO,CuAl ₂ O ₄ 41 159

031 CuO, CuAl ₂ O ₄ 61 177

032 CuO, CuAl ₂ 0 ₄ 70 126

033 CuO, CuAl ₂ 0 ₄ 80 98

001 CuO,CuCr ₂ 0 ₄ -47 100

Example 27

Effects of Sodium Content ofthe Cu-Al-O Catalvst on Hvdrogenolvsis

Table 19. below, shows the chemical and physical properties of Cu-Al-O

catalysts of the present invention having different sodium contents. All of the

catalysts were prepared from the same batch. However, the sodium content varied

due to the amount of washing. As stated above with reference to Table 3, proper

washing, i.e. four washes can reduce the sodium content to < 1%.

Catalyst # 011 was not washed. Catalysts # 012, # 013, # 014, # 015 and # 016

were subjected to 1, 2, 3, 4 and 5 washings, respectively. Each washing use the

same volume of de-ionized water.

Table 19

Physical/Chemical Properties and CFA Hydrogenolysis Activity of Cu-Al-O

Catalysts with Different Sodium Content

Catalyst 011 012 013 014 015 016 I.D. #

CFA 11 22 69 138 158 175

Activity of E-118, %

CuO% 51.7 55.8 58.3 58.0 59.6 58.2

Al ₂ O ₃ % 32.8 35.4 37.3 37.9 37.5 37.37

Na ₂ O, % 5.26 2.79 1.29 0.36 0.09 0.02

LOI % 3.72 3.86 2.72 1.98 2.35 1.95 (950°C)

Leachable 2.04 8.80 7.89 2.32 2.30 2.17

Cu, %

Leachable 4.05 2.41 1.42 0.72 0.76 0.60 Al, %

S.A., m ² /g 24 44 48 43 42 35

Generally, as indicated by the washed samples, the lower the sodium content,

the lower the leachable cations (Cu and Al). The surface area and leachable copper

in the unwashed sample is unexpectedly low. There is, however, a relationship

between the low sodium content and activity on coconut fatty acid hydrogenolysis,

as best illustrated in Fig. 9. The lower the sodium content, the better the catalytic

activity. A sodium oxide content less than 0.5% produces optimal catalytic activity

for this particular application.

Example 28 Effect of Catalyst Reduction On Coconut Fatty Acid Hydrogenolysis

As shown above in Table 16, catalytic activity tests indicated that catalyst

calcined at 1000°C (catalyst ID # 008) had reduced catalytic activity. The

decreased activity originally was assumed to be due to difficulty in achieving

catalyst reduction at that temperature. To determine if additional reduction would

improve catalyst activity, catalyst ID #008 was further reduced an additional hour at

300°C and 4400 psi hydrogen . The results are shown in Table 20.

Table 20 Effects of Reduction on Catalyst ID #008 Hydrogenolysis Activity

As can be seen, the extended reduction did not increase activity but

dramatically decreased the activity and selectivity for this high temperature

(1000°C) calcined catalyst.

In a separate test, catalyst ID # 034 calcined at 800°C, (similar composition to

catalyst ID # 16 and # 31) was tested for hydrogenolysis activity at normal

reduction and one hour extended reduction at 300°C and 830 psig hydrogen. The

results are shown in Table 21.

Table 21 Effects of Reduction on Catalyst ID # 034 Hydrogenolysis Activity

Catalyst Activity, % of Rate of Dodecane Dodecane % at Reduction Standard Catalyst Formation, 1.5% Ester Condition # 001 K* 1,000 remaining

500 Psi H ₂ , 182 3.44 0.1 1 heated from room temp, to

300° C, final pressure was 830

Psig above + hold at 186 4.25 . 0.13 300° C and 4400 Psig for one hour

As shown in Table 21, the extended reduction resulted in little change in the

overall activity or the selectivity to hydrocarbon, as indicated by the dodecane %

and rate of dodecane formation.

Example 29 Hvdrogenolvsis of Methyl Laurate

Catalyst ID # T-3 of the present invention was tested for methyl laurate hydrogenolysis activity. The results are listed in Table 22.

Table 22 Hydrogenolysis of Methyl Laurate on Different Cu-based Catalysts

Catalyst ID # T-3 (Cu/Al) T-20 (Cu/Cr)

Cat. = 27.31 g/30 ml Cat. = 47.41 g/30 ml B.D. = 0.91 g/ml B.D. = 1.58 g/ml

185° C

LHSV, l/hr* 0.74 0.73

WHSV, l/hr** 0.71 0.40

Conv. % 91.9 94.97

200°C

LHSV, l/hr 0.74 0.74

WHSV, l/hr 0.71 0.41

Conv. % 98.42 98.87

* Liquid hourly space velocity ** Weight hourly space velocity

It will be appreciated by those skilled in the art that the reaction temperature

and LHSV in industrial applications are 200°C and 0.5 to 1 hour ^'1 , respectively.

Under industrial conditions the two catalysts will be active enough to reach

equilibrium conditions. In fact, at 200°C, with LHSV= 0.74 hr ^*1 , the reaction is

close to equilibrium. Because of the large differences in bulk density between Cu-

Al-O catalysts and Cu/Cr catalysts, the rate at the same weight and hourly space

velocity (WHSV) of the novel Cu-Al-O catalysts are significantly higher than that

of Cu/Cr catalysts.

Other Applications

The foregoing applications and characterizations demonstrate that the non-

chrome containing Cu-Al-O catalysts of the present invention exhibits catalytic

activity, selectivity and stability equal to or superior to the chromium containing

copper catalysts presently employed in many commercial applications. In addition

to this, Cu-Al-O catalyst of the present invention does not have the environmental

problems associated with the conventional chromium containing copper catalysts.

Furthermore, it will be appreciated that the novel Cu-Al-O catalysts of the

present invention may be employed in a large number of applications not

specifically discussed herein. For example, the Cu-Al-O catalyst may be

substituted for prior art catalysts disclosed above. By way of particular example,

the Cu-AI-O catalyst of the present invention can be used in the hydrogenation

applications disclosed in U.S. Patent 5,243,095 to Roberts et al. These reactions

may include, but are not limited to, a number of alkylation reactions,

dehydrogenation reactions, hydrogenation reactions, reductive amination,

hydrogenation of nitriles to unsaturated secondary amines, oxidation and reduction

reactions. These include alkylation of phenol with alcohols; amination of alcohols;

dehydrogenation of alcohols; hydration of nitrile; hydrogenation of aldehydes;

hydrogenation of amides; hydrogenation of fatty acids via esterification and

hydrogenolysis; selective hydrogenation of fats and oils; hydrogenation of nitriles;

hydrogenation of nitroaromatic hydrocarbons; hydrogenation of ketones;

hydrogenation of furfural; hydrogenation of esters; hydrogenation of carbon

monoxide to methanol; oxidation/incineration of carbon monoxide; oxidation of

vapor organic compounds (VOC); oxidation of SO ₂ ; oxidation of alcohols;

decomposition of nitric oxide; selective catalytic reduction of nitric oxide; and

purification of a gas stream by the removal of oxygen.

Moreover, various changes and modifications may be made in the catalyst of

the present invention, in the method of preparing the same, and in the reactions

catalyzed by it, without departing from the scope of the appended claims.

Therefore, the foregoing description and accompanying figures are intended to be

illustrative only and should not be construed in a limiting sense.