AU625730B2 - Low pressure catalytic hydrogenation of carbonyl-containing compounds and catalysts therefor - Google Patents

Description

AU-AI -23184/88 WORLD INTELLECTUAL PROPERTY ^A ITI Pcr International Bureau INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT) (51) International Patent Classification 4 (11) International Publication Number: WO 89/ 00886 BO1J 23/60, 37/00, CO7C 29/14 Al C07C 29/136 (43) International Publication Date: 9 February 1989 (09.02.89) (21) International Application Number: PCT/US88/02576 (74) Agent: REITER, Stephen, 343 State Street, Rochester, NY 14650 (US).

(22) International Filing Date: 29 July 1988 (29.07.88) (81) Designated States: AU, DE (European patent), FR (Eu- (31) Priority Application Numbers: 081,252 ropean patent), GB (European patent), IT (European 150,791 patent), JP, KR, NL (European patent).

219,630 (32) Priority Dates: 3 August 1987 (03.08.87) Published 1 February 1988 (01.02.88) With international search report.

July 1988 (15.07.88) Before the expiration of the time limit for amending the claims and to be republished in the event of the receipt (33) Priority Country: US of amendments.

(71) Applicant: EASTMAN KODAK COMPANY [US/US]; 198 343 State Street, Rochester, NY 14650 P. 2 0 A 189 (72) Inventors: GUSTAFSON, Bruce, Leroy 831 Sir Echo AUSTRALIAN Drive, Kingsport, TN 37663 WEHNER, Paul, Sherman 4017 Lakewood Drive, Kingsport, TN 1 MAR 1989 37663 MERCER, Patricia, Lee, Nixon 5039 Dublin Road, Kingsport, TN 37664 NELSON, PATENT OFFIC 1 Gregory, Otis 1136 Olympus Drive, Kingsport, TN 37663 (US).

(54) Title: LOW PRESSURE CATALYTIC HYDROGENATION OF CARBONYL-CONTAINING COMPOUNDS AND CATALYSTS THEREFOR (57) Abstract Process for the hydrogenation of carbonyl-containing compounds at mild conditions of temperature and pressure to produce alcohols is disclosed, employing palladium and zinc-containing catalysts. Methods for the preparation of the palladium and zinc-containing catalysts useful for the desired reductive conversion are also disclosed.

I

r i (11) AI-B-23184/88 -2- (10)625730 reduction of at least a portion of the palladium to less than the +2 oxidation state.

A process for the low pressure hydrogenation of carbonyl-containing compounds to produce the corresponding alcohol, wherein said carbonyl-containing compounds have the structure: 0

R-C

z wherein R is a C 1

-C

20 alkyl or substituted alkyl radical; or a C 2

-C

20 alkenyl or alkynyl radical or a substituted derivative thereof; wherein said substituted groups include ethers, amines, additional carbonyl groups, aryl groups, hydroxyl groups and alkoxy groups; and

Z=H,

wherein R' is defined the same as R, and is selected independently of R, OR', wherein R' is as defined above, X, wherein X is any one of the halogens, or

NR"

2 wherein each R" is independently selected from H or R'; with the proviso that R and Z can be joined as part of a polymethylene or hydrocarbyl- or heteroatom-substituted polymethylene radical, poly-carbonyl analogs of such carbonyl-containing compounds; and /3

L

1 111 .3 1 I (11)AU-B-23184/88 -3- 625730 mixtures of any two or more thereof; said process comprising contacting said carbonyl-containing compounds with a palladium on zinc oxide catalyst comprising 0.01 up to 20 wt palladium calculated as the metal and based on the total weight of catalyst; and wherein the atomic ratio of Pd to Zn falls within the range of about 0.01 up to 10; wherein said contacting is carried out in the presence of hydrogen under hydrogenation conditions.

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-2- Description LOW PRESSURE CATALYTIC HYDROGENATION OF CARBONYL-CONTAINING COMPOUNDS AND CATALYSTS THEREFOR This invention relates to catalytic hydrogenation. In one aspect, the present invention relates to a process for the selective reduction of carbonylcontaining compounds to alcohols. In another aspect, the present invention relates to catalysts useful for the selective reduction of carbonyl-containing compounds to alcohols, and methods for preparing such i "catalysts.

The catalytic hydrogenation of carbonylcontaining compounds, esters, to produce their 15 corresponding alcohols, is potentially of great commercial value. Catalysts traditionally employed for such conversions include copper chromite based materials, frequently containing a promoter such as barium. Unfortunately, these catalysts typically require high pressure to achieve commercially attract ive reaction rates for the hydrogenation of esters, pressures in excess of 3000 psig. In addition, echromium and barium present toxicity and environmental concerns which must be dealt with if one is to economically and safely use these materials on a commercial scale.

More recently, substantial amounts of research have been carried out in efforts to develop hydrogenation catalysts capable of reducing carbonylcontaining compounds, organic acids and esters, to alcohols at reduced pressures. While such catalysts are capable of promoting the hydrogenation of carbonyl-containing compounds to produce alcohols, I one problem with such materials is the need to run at At, /f r T- :TT i 1~ -3 very low liquid hourly space velocities in order to achieve suitably high conversion levels.

Another problem frequently encountered with such prior art low pressure catalyst systems when employed for the reduction of carbonyl-containing compounds such as aldehydes and ketones, is their lack of selectivity to the desired alcohol product, such catalysts frequently being too active and thus producing product which results from reaction of substrate with additional hydrogen.

Yet another problem encountered with such prior art low pressure catalyst systems, such as Raney nickel, is the ease of handling of such catalysts, I which are frequently pyrophoric, and thus require special handling to avoid fire hazard.

i Objects of the Invention An object of the present invention, therefore, is a process for the low pressure, high selectivity, high activity hydrogenation of carbonyl-containing 20 compounds to produce alcohols.

Another object of the present invention is a S.catalyst system which is capable of promoting the hydrogenation of carbonyl-containing compounds at low reaction pressures.

Still another object of the present invention is a catalyst system which is capable of promoting the hydrogenation of carbonyl-containing compounds at low reaction pressure, which catalyst system is readily prepared and requires no special handling precautions.

These and other objects of the present invention will become apparent from inspection of the detailed description and the appended claims which follow.

k -p 44C 41

A

I I F al -4- Statement of the Invention In accordance with the present invention, it has been discovered that palladium supported on zinc oxide is an effective catalyst for the low pressure hydrogenation of carbonyl-containing compounds to selectively produce alcohols in high yield.

The invention hydrogenation process employs readily prepared, easily handled catalysts and enables a commercially important reaction, the conversion of carbonyl-containing compounds to alcohols, to be carried out at low reaction pressures, thereby reducing the cost of equipment required for the desired hydrogenation reaction and reducing the safety risks involved in such conversions.

Detailed Description of the Invention 15 In accordance with the present invention there is eeoc provided a method for preparing high activity, low pressure hydrogenation catalysts comprising palladium on zinc oxide support, which method comprises: S(a) contacting said zinc oxide support or a precursor thereof with palladium or a reducible compound thereof; i optionally calcining the resulting palladiumtreated zinc oxide support or precursor thereof in the presence of an oxygen-containing gas at a temperature in the range of 200 up to 400°C for :a time sufficient to remove substantially all of the counter-ions associated with said palladium or reducible compound thereof and said zinc oxide support or precursor thereof; and contacting the optionally calcined palladiumtreated zinc oxide support with a reducing atmosphere under conditions sufficient to cause reduction of at least a 'portion of the palladium to less than the +2 oxidation state.

In accordance with another embodiment of the present invention, there is provided a process for the low pressure hydrogenation of carbonyl-containing compounds of specified structure to produce the corresponding alcohols, which /iO439 process comprises contacting the carbonyl-containing

II

compounds with a catalyst comprising 0.01 up to 20 weight percent palladium on a zinc oxide-containing support in the presence of hydrogen under hydrogenation conditions.

Catalysts employed in one embodiment of the present invention comprise palldium on zinc oxide support. A wide variety of techniques for contacting palladium and zinc oxide are suitable. For example, palladium can be applied directly to preformed zinc oxide employing such techniques as incipient wetness, wet impregnation, metal atom evaporation, precipitation, or appropriate precursors of palladium and zinc can be coprecipitated, then calcined to remove the counter ions introduced by the precursor i compounds, and, finally, reduced to convert the palladium to an active form.

i 15 A wide range of zinc compounds are suitable zinc oxide precursors for use in the practice of the .present invention, zinc nitrate, zinc halides, Szinc acetate, zinc carbonate, and the like.

i *When zinc oxide is employed as catalyst support, S. 20 a variety of zinc oxide compounds can be directly employed as catalyst support. Typically, such preformed zinc oxide materials will contain an impurity content no greater than about Preferred zinc oxide compounds employed as catalyst support will contain at least 60% zinc oxide by weight, with up to 40% by weight of inert materials such as: SioD Al 2 0 3 and TiO being employed as inert diluents and as catalyst binders.

The surface area of the catalyst supports employed in the practice of the present invention can vary widely. Preferably, support materials employed in the practice of the invention will have surface ^^3,9 i -I' 1I; ii ii I 1,

II

6 areas of at least about 1 m Of course, those of skill in the art also recognize that higher surface area materials will generally produce higher activity catalysts than lower surface area catalysts having comparable composition.

When zinc oxide support is prepared by calcination of a precipitated zinc oxide precursor, temperatures in the range of about 200 up to 400 0 C are generally employed. Such temperature is maintained for a time sufficient to remove substantially all the counter ions introduced by the zinc oxide precursor (and the palladium compound employed) to form the catalyst. Times in the range of about 2 up to 8 hours or longer are generally effective for this 15 purpose.

Suitable sources of palladium are any compounds which are reducable when subjected to reducing conditions. Since many palladium compounds are convertible to the oxide form upon calcination under 20 the above-described conditions, and the oxides of palladium are readily reduced, many palladium compounds are useful for catalyst preparation.

Exemplary palladium compounds include the palladium halides, palladium acetate, palladium nitrate, palladium ammine complexes, organometallic complexes of palladium, and the like.

1^'/f r r wnuy BpBr' 0 1 7 Finally, the Pd-treated support can optionally be subjected to a reducing atmosphere under conditions sufficient to cause reduction of at least a portion of the palladium to less than the +2 oxidation state.

The term "carbonyl-containing compounds" as employed in this specification is intended to include compounds of the structure 0

II

R-C

Z

wherein R is a C 1

-C

20 alkyl or substituted alkyl radical; or a C 2

-C

20 alkenyl or alkynyl radical or substituted 15 derivative thereof; i wherein said substituted groups include ethers, amines, additional carbonyl groups, aryl groups, hydroxyl groups and alkoxy groups; and b S* 3 9 JM NrO p* 2 8-

Z=H,

wherein R' is defined the same as R, and is selected independently of R, OR', wherein R' is as defined above, X, wherein X is any one of the halogens, or NR" wherein each R" is independently selected from H or R'; with the proviso that R and Z can be joined as part 'of a polymethylene or hydrocarbyl- or heteroatom- 10 substituted polymethylene radical, poly-carbonyl analogs of such carbonyl-containing compounds; and mixtures of any two or more thereof.

R*

Preferred carbonyl-containing compounds are j 15 compounds selected from the group consisting of:

YO

2

C-A-CO

2 Y wherein A is an alkylene moiety, an alkenylene moiety, or an alkynylene moiety having 1 up to carbon atoms, or substituted derivative thereof, or a cycloalkyl or cycloalkenyl moiety having 4-12 carbon atoms or substituted derivative thereof; and wherein each Y is independently a C up to C12 alkyl, alkenyl or alkynyl radical or substituted derivative thereof; B-CO2 Y t kF**AV 9 wherein B is an alkyl, alkenyl or alkynyl radical, or substituted derivative thereof, having 1 up to carbon atoms; and wherein Y is defined as above;

Z~-H

wherein Z is an alkyl, alkenyl or alkynyl radical having 1 up to 20 carbon atoms or substituted derivatives thereof; and mixtures of any two or more thereof.

10 Exemplary carbonyl-containing compounds which satisfy the above formulae include alkyl oleates, dialkyl adipates, propionaldehyde, dialkyl cyclohexane dicarboxylates, alkyl acrylates, alkyl propionates, alkyl isobutyrates, alkyl normal 15 butyrates, alkyl acetates, nonanal, dialkyl butane dicarboxylates, alkyl methacrylates, alkyl crotonates, alkyl isocrotonates, alkyl sorbates, alkyl cinnamates, maleic anhydride, alkyl fumarates, dialkyl succinates, succinic anhydride, alkyl .20 glutarates, dialkyl malonates, dialkyl octanedioates, dialkyl decanedioates, dialkyl dodecanedioates, alkyl laurates, alkyl myristates, alkyl palmitates, alkyl stearates, alkyl linoleates, alkyl linolenates, alkyl isovalerates, alkyl normal valerates, alkyl caproates, alkyl caprylates, alkyl 2-ethylhexanoates, dialkyl cyclohexanedioates, butyrolactone, alkyl phenylacetates, alkyl cyclohexane carboxylates, alkyl pyruvates, alkyl glycolates, alkyl oxalates, alkyl formates, alkyl lactates, alkyl citrates, glyceride esters, and the like.

10 *8 I 88 8 8* 8*.

8* 8 8.

8

'A.

Typical alkyl groups employed have from 1 up to carbon atoms, with alkyl groups having 1 up to 6 carbon atoms being preferred.

The hydrogenation process of the present invention involves contacting at least one of the abovedescribed carbonyl-containing compounds with at least one of the above-described palladium/zinc oxide catalysts in the presence of hydrogen under hydrogenation condtions. Hydrogenation conditions typically employed in the practice of the present invention are set forth below.

The process of the present invention can be operated in a variety of configurations. Depending on the substrate to be hydrogenated, the preferred method of operation is frequently in a fixed bed flow reaction system. If the vapor pressure of the substrate to be hydrogenated is sufficiently high at reaction temperature, the desired method of operation may be vapor phase, all reactants and products 20 exist in the gaseous phase. For other substrates, the desired method of operation may be a trickle bed configuration. Regardless of the method of operation, the desired time of contact between the reactants and catalyst components can be varied as desired to achieve the desired level of reaction.

In typical fixed bed operation, pressures in the range of 100-10,000 psig will be employed.

Preferably, the pressure will be in the range of 100-2500 psig. Similarly, temperatures in the range of 25-400 0 C can be used, with a more perferred range of 100-290 0 C. While the feed rate of the substrate will be varied to control the level of conversion, normal liquid hourly space velocities (LHSV) will be -l in the range of about 0.01-100 h with a -35 preferred range of 0.1-20 h preferred range of 0.1-20 h The molar ratio of 11 hydrogen to substrate will typically be in the range of 1:1 to 1000:1 with a preferred range of 2:1 to 100:1.

Alternatively the invention may be conducted in a slurry phase reactor. In slurry phase operation, the ratio of carbonyl-containing compound to catalysts employed can vary widely, with ratios as low as 1:1 or lower being operable, but not economically attractive; and ratios as high as 10,000:1 and higher also being operable, but generally providing relatively low conversions unless very long contact times are employed. Preferred carbonyl-containing compound:catalysts ratios fall within the range of about 1:1 up to 1,000:1, with ratios in the range of 15 about 2:1 up to 100:1 being most preferred because good levels of conversion of the carbonyl-containing compounds are obtained without requiring excessive amounts of catalysts, or extremely long contact times.

20 While the invention hydrogenation process can be ,carried out in the absence of solvent, it is presently preferred to perform the process in the presence of a suitable solvent. Suitable solvents are compounds which are fluid and in which the 25 carbonyl-containing starting material is soluble at reaction temperature, and which are non-reactive under hydrogenation conditions. Preferred solvents are those which are fluid and in which the carbonylcontaining starting material is soluble at room temperature. Exemplary solvents include aromatic solvents such as toluene; alcohols such as methanol; ethers such as diphenyl ether and tetrahydrofuran; and the like.

12 When employed, the volume/volume ratio of solvent to substrate can vary widely, typically falling in the range of about 5:95 to 95:5.

In a preferred embodiment of the present invention, hydrogenation of carbonyl-containing compounds is carried out with small amounts of water 0.01 up to about 2 wt. water based on the total weight of reactants and solvent) present in the reaction mixture. It has been found that selectivity to hydrogenation (as opposed to transesterification between reactant and product) products is greatly improved by the presence of such small quantities of water in the reaction mixture.

Following hydrogenation, the desired product can be recovered and purified using conventional techniques well known to those of skili in the art.

For example, catalysts can be removed from the reaction mixture by filtration, decantation and the like. By-products and unreacted starting material as 20 well as solvent, if employed, can be separated from the product by distillation, recrystallization, solvent/solvent extraction, and the like.

The invention will now be described in greater detail by reference to the following non-limiting examples.

EXAMPLE 1 Catalyst Preparation Pd on ZnO Support A sample of 1 wt Pd supported on ZnO was prepared as follows: A solution of Pd was prepared by dissolving 20 g of Pd(NO 3 2 in 50 ml of and 16 g of HNO 3 This solution was diluted to 750 ml and added to 925 g of powdered ZnO. The resulting mixture was heated at 90 0 C in ir until dry. The rdi~i' F~u 13 sample was then calcined at 200 C for two hours prior to catalytic evaluation. Approximately 1 cc of powdered sample was loaded into a plug flow micro-reactor and heated to 300°C in flowing hydrogen. The catalyst was held at 300 0 C for two hours prior to evaluation for hydrogenation of carbonyl-containing compounds.

EXAMPLE 2 Methyl Acetate Hydrogenation; Effect of Water in the Feed Catalyst prepared as described in Example 1 was employed for the vapor phase hydrogenation of methyl 14 acetate. All evaluations were conducted using a hydrogen/ester ratio of 4.0 and a gas hourly space velocity (GHSV; volume of gas/volume of catalyst/hr)

-I

of 30,180 hr The effect of water content in the feed is demonstrated by the results presented in Table I.

Table I Catalytic Hydrogenation over Pd/ZnO Run Temp., Pressure, #L C psig Rate (imoles/ g-cat sec)* MeOH EtOH EtOAc 1 2 3 4 298 298 298 296 730 720 720 725 wt H20 0.0 0.1 0.5 1.0 7.3 4.3 2.8 1.5 2.0 2.4 1.5 1.1 3.6 1.8 0.3 0.1 *MeOH methanol EtOH ethanol EtOAc ethyl acetate The results set forth in Table I demonstrate that the addition of small amouncs of water to the reaction mixture promotes improved catalyst performance by reducing the occurrence of undesired transesterification by-product formation.

EXAMPLE 3 Hydrogenation of Methyl Acetate a. Pd on ZnO Catalyst Catalyst prepared as described in Example 1 was evaluated in the manner described in Example 2. The

'H

1.vl '17~ ~b OpaC

F

T

i I water content of the feed was approximately 1% by weight for all of the runs carried out. Results from these evaluations are presented in Table II.

Table II Catalytic Evaluation of Pd/ZnO Methyl Acetate Hydrogenation

H

2 Run Temp., Press., Ester, °C psig moles Rate (umoles/ a-cat sec)* MeOH EtOH EtOAc eoo° oe ea e o o: go *e *J 296 295 307 333 570 735 980 735 0.34 0.34 0.15 3.97 2.1 2.5 7.1 11.0 1.4 1.8 5.9 9.0 <0.01 0.05 0.7 0.8 15 *MeOH methanol EtOH ethanol EtOAc ethyl acetate The results set forth in Table II demonstrate that Pd/ZnO catalyst is effective for the conversion of esters with high selectivity to the corresponding alcohols at pressures below 1000 psig. In addition, excellent catalyst performance is obtained under a variety of the reaction parameters, temperature,.pressure and feed composition.

I.

16 EXAMPLE 4 Hydrogenation of Methyl Propionate Pd/ZnO Catalyst The catalyst prepared as described in Example 1 was evaluated in the same manner as described in Example 2 for the hydrogenation of methyl propionate. Reaction parameters and results from this evaluation are given below.

Temperature 333 C Pressure 710 psig

H

2 /ester 4.8 f-1 GHSV 29,178 h SConversion -16. methanol propanol Rate (pmoles/g-cat sec): 12. S*i These results demonstrate that Pd/ZnO is an effective i catalyst for the hydrogenation of methyl propionate to 20 propanol and methanol. Note the very high reaction rates obtained even under non-optimized reaction conditions.

i EXAMPLE 5 Hvdrogenation of Methyl n-Butyrate The catalyst prepared as described in Example 1 was 25 evaluated in the same manner as described in Example 2 for the hydrogenation of methyl n-butyrate. Reaction parameters and results from this evaluation are given below.

17 Temperature Pressure

H

2 /ester

GHSV

Conversion 333 0

C

725 psig 5.6 28,410 h-i 17. methanol n-butanol 5.9 6.1 Rate (Imoles/g-cat sec): The results demonstrate that Pd/ZnO is an effective catalyst for the hydrogenation of methyl n-butyrate to n-butanol and methanol.

EXAMPLE 6 Hydrogenation of Methyl i-Butyrate The catalyst prepared as described in Example 1 was evaluated in the same manner as described in Example 2 for the hydrogenation of methyl i-butyrate. Reaction parameters and results from this evaluation are given below.

Temperature Pressure

H

2 /ester

GHSV

Conversion 334 0

C

725 psig 5.7 28,372 h-1 25. methanol i-butanol 2.9 Rate (moles/g-cat sec): These results demonstrate that Pd/ZnO is an effective catalyst for the hydrogenation of methyl i-butyrate to i-butanol and methanol. Even under these non-optimized reaction conditions, the per pass conversion was EXAMPLE 7 Hydrogenation of Ethyl Acetate Pd/ZnO Catalyst The catalyst prepared as described in Example 1 was evaluated in the same manner as described in i I 18 Example 2 for the hydrogenation of ethyl acetate. Reaction parameters and results from this evaluation are given below.

Temperature 332°C Pressure 725 psig H2/ester 4.9 GHSV 29,100 h Conversion 16. 110 Ethanol Rate (pmoles/g-cat sec): 16.7 These results demonstrate that Pd/Zno is an effective catalyst for the hydrogenation of ethyl acetate to ethanol.

15 Note the high selectivity and very high rate of reaction S*even under these non-optimized conditions.

i: *EXAMPLE 8 Hydrogenation of 1,4-Dimethylcyclohexane Dicarboxvlate i 20 A catalyst was prepared in the same manner as ,described in Example 1. For catalytic evaluation 260 cc of catalyst (14X40 standard mesh particles) was loaded into a 1 inch fixed bed reactor. The 1- -i 19

:I

I

i

L

It sample was treated in a hydrogen flow while heating the catalyst to reaction temperature. The system pressure was then increased to the desired reaction pressure. The ester feed consisted of 10 wt% 1,4dimethylcyclohexane dicarboxylate (DMCD) in 1-dodecanol. Catalytic evaluation was conducted using a liquid feed rate of 80 g/h, 290 0 C, 1250 psig, and a 1000 standard cubic centimeters (sccm) hydrogen flow. Under these conditions, the DMCD conversion was 93.3%. The observed products were 60 mol cyclohexanedimethanol (CHDM) and 40 mole 1-methyl, 4-dodecyl, cyclohexanedicarboxylate.

The above-described catalyst and reaction set-up were employed in the same manner as described except 15 that the reaction conditions were changed to a liquid feed rate of 13 g/h, 300 0 C, 1250 psig, and 130 seem hydrogen. Under these conditions, the observed conversion of DMCD was 99.5% with 93.3% molar selectivity to CHDM.

These results demonstrate that Pd/ZnO is a very effective catalyst for the selective hydrogenation of DMCD to CHDM.

EXAMPLE 9 Effect of Support Surface Area on Catalyst Performance Catalyst samples were prepared as described in Example 1 except that various sources of ZnO were used for the catalyst support.

I II 20 Table VI Catalytic Evaluation of Pd/ZnO Methyl Acetate Hydrogenation Temperature 300°C Pressure 720 psig

H

2 /Ester Water 1 wt Rate (imoles/ BET R-cat sec)* Run Surface Area, ZnO Source m 2 /g MeOH EtOH EtOAc 15 A 3.3 3.0 2.4 0.2 16 B 4.7 2.8 2.0 0.2 17 C 4.3 2.8 2.3 0.1 18 D 27.0 6.0 5.8 0.4 *MeOH methanol EtOH ethanol EtOAc ethyl acetate These results demonstrate that a variety of zinc oxide-containing support materials are useful supports for the Pd/ZnO catalyst of the present invention. In addition, the results show that the rate of reaction with Pd/ZnO catalyst is greatly improved with higher surface area support.

EXAMPLE 10 Catalyst with Modified Catalyst Support: ZnO/Al 2 03 ZnO/Al203 was prepared by dissolving 365 g of zinc nitrate in 800 ml of water at 60 0 C. A solution of Na 2

CO

3 (160 g/700 ml) was slowly added to the Zn solution while stirring to precipitate the Zn.

21- The resulting precipitate was washed in 1000 ml of water, filtered and dried at 90 0 C. The resulting solid was heated in a flow of air at 350 0 C for four hours. A portion of this solid (50 g) was added to 32 g of aluminum hydrate and 200 ml of water. This mix was blended for 20 minutes, filtered, and finally heated in a flow of air at 350 0 C for four hours. The resulting powder had a BET surface area of 79 m The final Pd/ZnO, Al 2 0 3 catalyst was prepared by adding an aqueous solution containing 0.24 g of Pd nitrate to 10 g of the ZnO/Al 2 0 3 support material, drying the resulting mixture at 90 0 C, and then heating in a flow of air at 250 0 C for four hours.

15 The catalyst was evaluated for methyl acetate hydrogenation activity as described in Example 2.

The reaction parameters employed and results obtained were as follows: Temperature 332 0

C

Pressure 720 psig

H

2 /ester 4.1 Wt% H20 0.0 GHSV 30,180 h-1 Methyl Acetate conversion 12.0% Product Rate (umoles/g-cst sec) CH OH 21.4 CH3CH2OH 5.6 CH3CO2CH2CH3 8.8 These results indicate that alumina can be added to the preparation of invention catalyst, if desired. It is of note that high selectivity to the desired hydrogenation products, methanol and ethanol, E d^ i a:i nl r 22 are obtained even at the high rates of reaction achieved with the Pd/ZnO-Al 03 catalyst.

EXAMPLE 11 Diethyl Adipate Hydrogenation A hydrogenation reaction was conducted as described in Example 8 except that diethyl adipate was used in place of DMCD and the catalyst volume was 100 cc. Operation conditions are given below: Temperature 300 0

C

Pressure 1233 psig .0 H 2 Feed Rate 760 seem Liquid Feed Rate 189 ml/hr Analyses of the liquid product stream gave the following results: 9499 9r 9 9 4.

5* 9* 99 4 9 Dodecyl alcohol 92% Diethyl adipate 2.2% 1,6-hexanediol 2.8%

C

6 products 3.% The results show that Pd/Zno is effective for the conversion of dibasic esters such as diethyl adipate to the corresponding diol.

EXAMPLE 12 Methyl Oleate HydroAenation Pd/ZnO Catalyst Hydrogenation of methyl oleate was carried out as described in Example 11 except that the liquid feed contained pure methyl oleate. The liquid feed rate was 68 ml/hr and the reaction temperature was 290 0

C.

Analysis of the product mixture gave the following results. g3 R.

1 /Cj P 7i Ell 23 Methyl oleate 4.1 wt Stearyl Alcohol 42 wt Oleyl Alcohol 50 wt These results demonstrate the utility of Pd/ZnO for the conversion of methyl oleate to a mixture of C-18 alcohols at low pressure. Of particular note is the fact that a significant portion of the hydrogenation product is the unsaturated product, oleyl alcohol. Isolation of this product is particularly noteworthy in view of the fact that the material has been subjected to reducing conditions in the presence 0 of a catalytic material Pd) which is generally quite effective for double bond hydrogenation. Thus, t* 0 hydrogenation in accordance with the present 15 invention is seen to be selective for reduction of carbon-oxygen double bonds carbonyl bonds) relative to carbon-carbon double bonds.

*0 oo: 7

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1 24 EXAMPLE 13 Hydrogenation of Propionaldehyde A Pd/ZnO catalyst prepared as described in Example 1 was evaluated for the vapor phase hydrogenation of propionaldehyde in a micro reactor system. Approximately 1 cc of catalyst was charged to the reactor and pretreated as described in previous examples. The reaction parameters employed and results obtained were as follows: Temperature 130 0

C

Pressure 800 psig

H

2 /Aldehyde GHSV 30,000 h-I Propionaldehyde conversion 49.0% i Product Selectivity, wt CH3CH2CH2OH 2-methyl-2-pentenal i 1 i ~8ir,~ 20 The results demonstrate the utility of Pd/ZnO catalyst for the conversion of propionaldehyde to propanol.

EXAMPLE 14 Hydrogenation of Nonanal A 1% Pd on ZnO catalyst prepared as described in Example 1 was evaluated for the slurry phase hydrogenation of nonanal. Nonanal (4g) was mixed with toluene (75 ml) and 1% Pd/ZnO (1 Ihis mixture was placed in a stirred autoclave and heated to 100 0 C under 100 psig hydrogen pressure. The

A'L

i 25 system was pressurized to 1500 psig and the mixture stirred for two hours. The autoclave was then cooled, vented and the resulting product mixture analyzed by gas chromatography For the comparative example, 1 g of a commercially available 1% Pd/Al203 was substituted for the Pd/ZnO catalyst. The results were as follows: GC Analysis, wt Catalyst Nonanal Nonanol Unknown 1% Pd/ZnO 0.9 99. 0.0 1% Pd/Al 2 0 3 28.7 60.2 11.1 i Pd/ZnO exhibits substantially higher activity and selectivity than Pd/A203 under identical conditions for the hydrogenation of nonanal.

i e i e

Claims (21)

1. 4- AP 26 The claims defining the invention are as follows:- i. A method for preparing high activity, low pressure hydrogenation catalysts comprising palladium on zinc oxide support, said method comprising: contacting said zinc oxide with palladium or a reducible compound thereof, wherein the quantity of said palladium employed is in the range of 0.01. up to 20 wt calculated as the metal and based on the total weight of palladium and zinc oxide support; optionally calcining the resulting palladium- treated zinc oxide support in the presence of an oxygen-containing gas at a temperature in the range of 200 up to 400 0 C for a time sufficient 15 to activate said palladium or reducible compound thereof and said zinc oxide component; and contacting the optionally-calcined palladium- treated zinc oxide support with a reducing atmosphere under conditions sufficient to cause reduction of at least a portion of the palladium to less than the +2 oxidation state. 2. A method in accordance with Claim 1 wherein said contacting step comprises contacting said support with palladium or a reducible compound thereof; wherein optional step is omitted; and wherein step comprises contacting said palladium-treated support with a reducing atmosphere under conditions sufficient to form highly dispersed, supported zerovalent palladium. 3. A method in accordance with Claim 1 or Claim 2 wherein the atomic ratio of Pd to Zn oxide falls within the range of about 0.01 up to 4. A method in accordance with any one of Claims 1 to 3 wherein said support has a surface area of at least about 1 m2/g.
2. 5. A method in accordance with any one of Claims 1 to 4 wherein the quantity of palladium employed is in the range of 0.5 up to 6 weight calculated as the method and based on the total weight of palladium and zinc oxide support. 39 6. A method in accordance with any one of Claims 1 to r 27 wherein the atomic ratio of Pd to Zn falls within the range of about 0.2 up to
3. 7. A method in accordance with Claim 1 wherein said calcination is carried out for a time in the range of about 0.5 up to 8 hours.
4. 8. A method in accordance with any one of Claims 1 to 7 wherein said reducing atmosphere comprises active hydrogen.
5. 9. A catalyst prepared by the method of Claim 1. A process for the low pressure hydrogenation of carbonyl-containing compounds to produce the corresponding alcohol, wherein said carbonyl-containing compounds have the structure: 0 R-C 15 Z I wherein R is a C-C 20 alkyl or substituted alkyl i radical; or 20 a C 2 -C 20 alkenyl or alkynyl radical or a substituted derivative thereof; wherein said substituted groups include ethers, amines, i additional carbonyl groups, aryl groups, hydroxyl groups and alkoxy groups; and i Z=H, wherein R' is defined the same as R, and is selected independently of R, OR', wherein R' is as defined above, X, wherein X is any one of the halogens, or NR" 2 wherein each R" is independently selected from H or R'; 19 with the proviso that R and Z can be joined as part of a I 28 polymethylene or hydrocarbyl- or heteroatom-substituted polymethylene radical, poly-carbonyl analogs of such carbonyl-containing compounds; and mixtures of any two or more thereof; said process comprising contacting said carbonyl-containing compounds with a palladium on zinc oxide catalyst comprising 0.01 up to 20 wt palladium calculated as the metal and based on the total weight of catalyst; and wherein the atomic ratio of Pd to Zn falls within the range of about 0.01 up to 10; wherein said contacting is carried out in the 15 presence of hydrogen under hydrogenation conditions.
6. 11. A process in accordance with Claim 10 wherein said contacting is carried out in the further presence of in the range of 0.01 up to 2.0 wt water, based on the total weight of reactants and solvent charged to the reactor. S* 20 12. A process in accordance with Claim 10 or Claim 11 wherein said hydrogenation conditions comprise a temperature S *in the range of 25 up to 400 C, and a pressure in the S. range of 100 up to 10,000 psig.
7. 13. A process in accordance with any one of Claims 10 to 12 wherein the hydrogen partial pressure falls within the range of 100 up to 10,000 psig.
8. 14. A process in accordance with any one of Claims 10 to S13 wherein said hydrogenation conditions comprise a temperature in the range of 100 up to 290 C and a pressure in the range of 100 up to 2500 psig. A process in accordance with any one of Claims 10 to 14 wherein the liquid hourly space velocity falls within the range of about 0.01 up to 100 h
9. 16. A process in accordance with any one of Claims 10 to 15 wherein the weight ratio of carbonyl-containing compound to catalyst falls within the range of 1:1 up to 10,000:1.
10. 17. A process in accordance with any one of Claims 10 to 16 wherein the carbonyl-containing compound is selected from 39 the group consisting of: 29 YO 2 C-A-CO 2 2 2 wherein A is an alkylene moiety, an alkenylene moiety, or an alkynylene moiety having 1 up to 20 carbon atoms, or substituted derivative thereof, or a cycloalkyl or cycloalkenyl moiety having 4-12 carbon atoms or substituted derivative thereof; and wherein each Y is independently a C 1 up to C 12 alkyl, alkenyl or alkynyl radical or substituted derivative thereof; B-CO 2 Y wherein B is an alkyl, alkenyl or alkynyl radical, or substituted derivative thereof, having 1 up to 20 carbon atoms; and ewherein Y is defined as above; 0 4 II Z-C-H i wherein Z is an alkyl, alkenyl or alkynyl radical having 1 i up to 20 carbon atoms or substituted derivatives thereof; and mixtures of any two or more thereof.
11. 18. A process in accordance with any one of Claims 10 to 17 wherein the carbonyl-containing compound comprises a dialkyl adipate.
12. 19. A process in accordance with any one of Claims 10 to 17 wherein the carbonyl-containing compound comprises a dialkyl cyclohexanedicarboxylate.
13. 20. A process in accordance with any one of Claims 10 to 17 wherein the carbonyl-containing compound is selected from 1 the group consisting of an alkyl oleate, an alkyl stearate, an alkyl linoleate, an alkyl linolenate, an alkyl a-el-costearate, an alkyl B-eleostearate, and mixtures of any two or more thereof.
14. 21. A process in accordance with any one of Claims 10 to I 17 wherein the carbonyl-containing compound comprises a dialkyl butanedicarboxylate. P' '39 22. A process in accordance with any one of Claims 10 to S0 4 f T i I 30 5. S 15 S S I S 17 wherein the carbonyl-containing compound comprises a glycerol ester.
15. 23. A process in accordance with any one of Claims 10 to 17 wherein the carbonyl-containing compound comprises a dialkyl glutarate.
16. 24. A process in accordance wdth any one of Claims 10 to 17 wherein the carbonyl-containing compound is selected from the group consisting of dialkyl fumarates, succinates, maleates, and mixtures of any two or more thereof.
17. 25. A process in accordance with any one of Claims 10 to 17 wherein the carbonyl-containing compound comprises an alkyl decanoate.
18. 26. A process in accordance with any one of Claims 10 to 17 wherein the carbonyl-containing compound comprises an 15 alkyl dodecanoate.
19. 27. A process in accordance with any one of Claims 10 to 17 wherein the carbonyl-containing compound is selected from the group consisting of alkyl acetates, propionates, butyrates, valerates, caproates, and mixtures of any two or more thereof.
20. 28. A process in accordance with any one of Claims 10 to 27 wherein said alkyl radical has in the range of 1 up to 6 carbon atoms.
21. 29. A method in accordance with Claim 1 substantially as 25 hereinbefore described with reference to any one of the examples. A process in accordance with Claim 10 substantially as hereinbefore described with reference to any one of the examples. DATED: 10 April, 1992 EASTMAN KODAK COMPANY By their Patent Attorneys: A PHILLIPS ORMONDE FITZPATRICK 8968m V i., i INTERNATIONAL SEARCH REPORT International Application No PCT/US 88/02576 I. CLASSIFICATION OF SUBJECT MATTER (it several classification symools apply, indicate all) According to International Patent Classification (IPC) or to both National Classification and IPC IPC 4 B 01 J 23/60; B 01 J 37/00; C 07 C 29/14; C 07 C 29/136 II. FIELDS SEARCHED Minimum Documentation Searched T Classification System Classification Symbols 4 IPC B 01 J; C 07 C Documentation Searched other than Minimum Documentation to the Extent that such Documents are Included In the Fields Searched Ill. DOCUMENTS CONSIDERED TO BE RELEVANT* Category j Citation of Document, with Indication, where appropriate, of the relevant passages iz Relevant to Claim No. 1 A FR, A, 1392376 (SNAM) 1 February 1965 A US, A, 2818393 (LEFRANCOIS) 31 December 1957 A I US, A, 4052467 (MILLS et al.) 4 October 1977 P,A EP, A, 0241760 (HENKEL) 21 October 1987 Special categories of cited documents: to later document published after the International filing date document defining the general state of the art which is not or priority date and not in conflict with the application but considered to be of particular relevance cited to understand the principle or Iteory underlying the cse invention earlier document but published on or attar the International invn 0 n "Efiarlier dtocument but publ d on or r ion X" document of particular relevance: the claimed invention cannot be considered novel or cannot be considered to document which may throw doubts on priority claim(s) or involve an inventive step which is cited to establish the publication date of another te c d Inv citation or other sDeclal reason (as specified) document of particular relevance! the claimed invention citation or other special reason (as seied) cannot be conaidered to Involve an Inventive step when the document referring to an oral disclosure, use, exhibition or document is combined with one or more other such docu- other means ments, such combination being obvious to a person skilled document published prior to the international filing date but In the art. later than the priority date claimed document member of the same patent family IV. CERTIFICATION uate of the Actual C.ompletlon of the International Search 6th December 1988 international Searching Authority EUROPEAN PATENT OFFICE Form PCT/ISA/210 (second sheet) (January 1985) Dale of Mailing of this International Search Report 2 2 DEC 1988 a ANNEX TO THE INTERNATIONAL SEARCH REPORT ON INTERNATIONAL PATENT APPLICATION NO. US 8802576 SA 24023 This annex lists the patent family members relating to the patent documents cited in the above-mentioned international search report. The members are as contained in the European Patent Office EDP file on 15/12/88 The European Patent Office is in no way liable for these particulars which are merely given for the purpose of information. Patent document Publication Patent family Publication cited in search report date member(s) date FR-A- 1392376 DE-C- 1213839 30-04-75 NL-A- 6405225 11-11-64 BE-A- 647710 09-11-64 LU-A- 46049 09-11-65 GB-A- 1024318 CH-A- 438269 US-A- 2818393 None US-A- 4052467 04-10-77 None EP-A- 0241760 21-10-87 DE-A- 3610698 01-10-87 3 For more details about this annex see Official Journal of the European Patei T No. 12/82