Catalyst compositions and the use thereof in the hydrogenation of carboxylic acid esters

Disclosed are catalyst compositions comprised of chemically-mixed, copper-titanium oxides and the use of such catalyst compositions in the hydrogenation of certain esters to obtain the alcohol corresponding to the acid residue of the ester.

This invention concerns certain novel chemically-mixed, copper-titanium 
oxide catalysts and the use of such catalysts in hydrogenating carboxylic 
acid esters to the alcohol which is analagous to the carboxylic acid 
portion of the ester. 
Processes for the hydrogenation of carboxylic acid esters (referred to 
herein simply as esters) to alcohols is of significant commercial 
importance. For example, dimethyl succinate can be hydrogenated to 
1,4-butanediol and dimethyl 1,4-cyclohexanedicarboxylate can be 
hydrogenated to 1,4-cyclohexanedimethanol. Both of these diols are used in 
substantial quantities in the manufacture of polyesters from which various 
molded articles and fibers are made. Another example is the manufacture of 
long chain alcohols by the hydrogenation of natural fats, i.e., glyceryl 
esters of long chain fatty acids. 
Catalysts normally used in the hydrogenation of esters to produce alcohols 
generally require extremely high pressures, e.g., greater than 4000 pounds 
per square inch (psi), to achieve commercially-feasible rates of 
conversion to the desired alcohol. The most commonly employed catalyst in 
such hydrogenations is copper chromite. 
We have discovered that chemically-mixed, copper-titanium oxide 
compositions are superior catalysts in processes for hydrogenating esters 
to alcohols. These catalytic compositions represent a substantial 
improvement over known ester hydrogenation catalysts in that they catalyze 
the hydrogenation of esters at satisfactory conversion rates and 
selectivity at pressures significantly below 4000 psi, typically below 
2500 psi. Moreover, our novel catalyst compositions do not contain toxic 
metals such as nickel or chromium and thus they are safer to manufacture 
and present fewer environmental problems and occupational hazards in their 
use and disposal. 
The catalyst compositions provided by this invention comprise 
chemically-mixed, copper-titanium oxides, i.e., a composition which 
contains --Ti--O--Cu-- bonds. These chemically-mixed oxide compositions 
may contain from 1 to about 75 weight percent copper oxide (calculated as 
CuO). However, catalytic activity for ester hydrogenation, especially when 
using the preferred conditions of temperature and pressure as described 
hereinbelow, is unsatisfactory when the copper oxide content of the 
compositions is below about 3, or above about 65, weight percent. 
Consequently, the copper oxide content of our novel catalyst compositions 
normally will be in the range of about 3 to 65 weight percent, based on 
the weight of the chemically-mixed, copper-titanium oxide. The preferred 
compositions contain about about 8.8 to 44.0 weight percent copper oxide 
(same basis). 
The essential ingredient, i.e., the chemically-mixed, copper-titanium 
oxides, of the novel catalyst compositions may be further defined by the 
formula 
EQU Cu.sub.x Ti.sub.y O.sub.z 
wherein x, y, and z represent atomic ratios and x is about 0.01 to 0.75, y 
is about 0.99 to 0.25 and z is about 1.99 to 1.25. The particularly 
preferred catalyst compositions are those wherein x is about 0.09 to 0.44, 
y is about 0.91 to 0.56 and z is about 1.91 to 1.56. 
In addition to the mixed copper-titanium oxides, the catalyst compositions 
may contain or be deposited on or in other materials. As our catalysts are 
developed for use in specific process, it may be advantageous to add minor 
amounts, e.g., up to about 10 weight percent, of other elements such as 
Li, Na, K, Rb, Cs, Mg, Ca, Sr, Ba, La, Ce or possibly others to the 
catalyst compositions to increase their lifetimes in commercial operations 
or to modify their activity and selectivity. It also may be desirable to 
add "structural promoters" to the catalysts to increase surface area or to 
change the acidity/basicity to optimze performance of the catalyst in a 
specific process. Such structural promoters as the oxides of silicon, 
aluminum, germanium boron, tin, zinc etc. can be combined with the 
catalysts during their preparation, replacing part of the titanium 
component but maintaining the concentration of the copper oxide in the 
catalysts within the range of about 3 to 65 weight percent. Alternatively, 
the catalyats may be deposited on such oxides, for example, by preparing 
the catalysts in the presence of such an oxide of a particular shape or 
particle size. 
Our novel catalyst compositions can be used in the form of powders, 
cylinders, spheres, honeycombs, etc the physical form being dictated by 
the type of reactor chosen for and by economic and engineering 
considerations associated with a particular hydrogenation process. 
Frequently, it will be desirable to use a binder to assist in the 
formation and maintenance of the compositions in a particular shape. For 
example, alumina, clays and zirconia are commonly used binders in the 
manufacture of commercial cayalyst pellets or cylinders. 
The catalyst compostions of this invention may be prepared by variety of 
methods. Generally, suitable procedures are dsescribed in Volumes 1 and 3 
of Studies in Surface Science and Catalysis, Elsevier Scientific 
Publishing Company. The source of the titanium component of our catalysts 
may be titanium tetrachloride, tetraisopropyl titanate, titania sol, 
titanium bromide, titanium butoxide, titanium methoxide, titanium 
butoxy-bis-(2,4-pentanedionate), titanium oxides, etc. Compounds which may 
be used as the source of the copper component include copper chloride, 
copper bromide, copper acetate, copper ethoxide, copper hydroxide, copper 
nitrate, copper gluconate, copper pentanedionate, copper oxides, etc. 
The titanium and copper compounds may be physically mixed, heated in air at 
temperatures above 500.degree. C., ground and then reheated. Where 
appropriate, hydrous titania can be precipitated and treated with a 
soluble copper salt such as a chloride, bromide, acetate or nitrate 
followed by drying and calcining in air at 550.degree. C. Another 
procedure comprises coating a soluble copper compound onto the surface of 
an amorphous form of titanium oxide (hydrous oxide), followed by calcining 
in air. The exact method of preparation is not critical so long as the 
formation of --Ti--O--Cu-- is achieved. This bonding distinguishes the 
essential or active ingredient of our catalysts from those in which copper 
is merely deposited on the surface of a support and exists primarily as a 
--Cu--O--Cu-- species. Other elements or compounds, such as those 
specified hereinabove, may be added to the titanium and copper sources 
during preparation of the catalyst. 
The esters which may be hydrogenated in accordance with the process 
provided by this invention are aliphatic, cycloaliphatic and aromatic 
esters of aliphatic and cycloaliphatic mono- and poly-carboxylic acids. 
The carboxylic acid residue of the ester reactants is not important to our 
process provided that each oxycarbonyl group hydrogenated is bonded to an 
aliphatic or cycloaliphatic carbon atom. For example, esters of 
arylcarboxylic acids such as alkyl benzoates are not included in the ester 
reactants in our process whereas esters aralkylcarboxyl acids such as 
alkyl phenylacetates are included within the meaning of esters of 
aliphatic acids. The aliphatic acid residues may be straight- or 
branched-chain, saturated or unsaturated and unsubstituted or substituted, 
for example with a wide variety of substituents such as halogen, hydroxy, 
alkoxy, amino, substituted amino, acylamido, aryl, cycloalkyl, etc, The 
main chain of the aliphatic acid residues may contain hetero atoms such as 
oxygen, sulfur and nitrogen atoms. 
Typically, the ester reactants employed in our process may contain up to 
about 40 carbon atoms. Examples of the carboxylic acid esters include the 
aliphatic, cycloaliphatic and aromatic esters of acetic propionic, 
butyric, valeric, hexanoic, heptanoic, octanoic, nonanoic, decanoic, 
undecanoic, lauric, tridecanoic, myristic, pentadecanoic, palmitic, 
heptadecanoic, stearic, oleic, linoleic, linolenic, nonadecanoic, 
eicosanoic, arachidonic, heneicosanoic, docosanoic, tetracosanoic, 
octacosanoic, triacontanoic, dotriacontanoic, acrylic, methacrylic, 
crotonic, 3-butenoic, cyclobutanecarboxylic, 2-norbornanecarboxylic, 
malonic, succinic, glutaric, maleic, glutaconic, adipic, pimelic, suberic, 
azelaic, sebacic, 1,2,4-hexanetricarboxylic, 1,2-, 1,3-, and 
1,4-cyclohexanedi- carboxylic, 2,6- and 
2,7-octahydronaphthalenedicarboxylic, 3-[(2-carboxyethyl)thio]butyric, 
etc. The alcohol segment of the ester reactants may be the residue of any 
mono- or poly-hydroxy compound such as methanol, ethanol, butanol, 
2-butanol, 2-ethylhexanol, 2,2-dimethyl-1,3-propanediol, ethylene glycol, 
propylene g1ycol, 1,4-butanediol, 1,6-hexanediol, 1,10-decanediol, 
cyclohexanol, benzyl alcohol, diethylene glycol, glycerin, 
trimethylolpropane, phenol, hydroquinone, etc. The hydrogenation process 
provided by our invention is particularly useful for converting lower, 
i.e., C.sub.1 -C.sub.4, alkyl esters, especially methyl esters, of 
C.sub.10 -C.sub.20 carboxylic acids and cyclohexanedicarboxylic acids, 
e.g., dimethyl 1,4-cyclohexanedi- carboxylic acid. 
The amount of catalyst required can be varied substantially depending on a 
number of factors such as, for example, the composition of the catalyst 
and the hydrogenation conditions being used. Furthermore, in certain modes 
of operation such as trickle bed or vapor phase processes using a fixed 
bed of catalyst, the amount of catalyst present relative to the ester 
reactant is difficult to define with any degree of precision. 
The hydrogenation conditions of pressure and temperature also can be varied 
depending not only on one another but also the activity of the catalyst, 
the mode of operation, selectivity considerations and the desired rate of 
conversion. Esters may be hydrogenated to their corresponding alcohols 
according to our novel process using temperatures in the range of about 
150.degree. to 350.degree. C. and hydrogen pressure in the range of about 
500 to 6000 psi. However, since hydrogenation rates generally increase 
with temperature, it is normally desirable to operate in the range of 
about 200.degree. to 300.degree. C. range to maximize both conversion 
rates and utilization of the commercial hydrogenation facility. While 
rates and conversions generally also increase with increasing pressure, 
the energy costs for compression of hydrogen, as well as the increased 
cost of high-pressure equipment render the use of the lowest pressure 
practical very advantageous. Thus, a highly attractive feature of our 
novel process is the use of hydrogen pressures below 3000 psi, especially 
in the range of about 600 to 2000 psi, which give good rates of 
conversion, especially when used in conjunction with a hydrogenation 
temperature in the range of about 250.degree. to 300.degree. C. 
The ester hydrogenation process of this invention may be carried out in the 
absence or presence of an inert solvent, i.e., a solvent for the ester 
being hydrogenated which does not affect significantly the activity of the 
catalyst and does not react with the hydrogenation product or products. 
Examples of such solvents include alcohols such as ethanol and lauryl 
alcohol; glycols such as mono- , di- and tri-ethylene glycol; hydrocarbons 
such as hexane, cyclohexane, octane and decane; and aromatic ethers such 
as diphenyl ether, etc. 
The hydrogenation process may be carried out as a batch, semi-continuous or 
continuous process. In batch operation a slurry of the catalyst in the 
reactant and/or an inert solvent in which the reactant has been dissolved 
is fed to a pressure vessel equipped with means for agitation. The 
pressure vessel then is pressurized with hydrogen to a predetermined 
pressure followed by heating to bring the reaction mixture to the desired 
temperature. After the hydrogenation is complete the reaction mixture is 
removed from the pressure vessel, the catalyst is separated by filtration 
and the product is isolated, for example, in a distillation train. 
Continuous operation can utilize a fixed bed using a larger particle size 
of catalyst, e.g., catalyst pellets. The catalyst bed may be fixed in a 
tubular or columnar, high pressure reactor and the liquid reactant, 
dissolved in an inert solvent if necessary or desired, slowly fed 
continuously above the bed at elevated pressure and temperature and crude 
product removed from the base of the reactor. Alternatively, the described 
fixed-bed catalyst system may be used in a gas-phase mode of operation 
wherein a reactant, which is sufficiently volatile under the hydrogenation 
conditions, is vaporized and passed through the catalyst bed, the off-gas 
is condensed and the product is isolated. Another mode of continuous 
operation utilizes a slurry of the catalyst in an agitated pressure vessel 
which is equipped with a filter leg to permit continuous removal of a 
solution of product in unreacted ester and/or an inert solvent. In this 
manner a liquid reactant or reactant solution can be continuously fed to 
and product solution continuously removed from an agitated pressure vessel 
containing an agitated slurry of the catalyst.

Our novel catalyst compositions and hydrogenation process are further 
illustrated by the following examples. 
PREATION OF CATALYST COMPOSITIONS 
Example 1 
Titanium tetraisopropoxide (172.1 g, 0.61 mol) was added dropwise to 500 mL 
water with rapid stirring. After the addition was complete, the slurry was 
stirred an additional hour. The solid was filtered and washed by 
reslurrying in water and filtering a second time. The solid was then 
reslurried in about 500 mL of water and the pH was adjusted to 10 with 
concentrated ammonium hydroxide. The slurry then was heated, with 
stirring, to and held at 60.degree. C. for three hours. The slurry was 
cooled with stirring and filtered. The solids collected were added with 
stirring to a solution of copper (I) acetate (10.26 g, 0.08 mol) in 450 mL 
water. The resulting slurry was heated, with stirring, to and held at 
60.degree. C. for three hours. The slurry was cooled to room temperature 
with stirring and then filtered and washed on the filter with water. The 
solid material collected was dried on a steam bath and then calcined in 
air for one hour at 200.degree. C., one hour at 350.degree. C. and three 
hours at 550.degree. C. The catalyst composition thus obtained contained 
8.8 weight percent copper, had a BET surface area of 9 square meters per 
g (m.sup.2 /g) and had the formula Cu.sub.0.11 Ti.sub.0.89 O.sub.1.89. 
Example 2 
Titanium tetraisopropoxide (71.2g, 0.25 mol) was added dropwise to 500 mL 
water with rapid stirring. After the addition was complete, the slurry was 
stirred an additional hour. The solid was filtered and washed once by 
reslurrying in water and filtering a second time. The solid was then 
reslurried in about 500 mL of water and the pH was adjusted to 10 by 
adding concentrated ammonium hydroxide dropwise with stirring. The slurry 
then was heated, with stirring, to and held at 60.degree. C. for three 
hours. The slurry was cooled with stirring and filtered. The solids 
collected were added with stirring to a solution of cupric acetate (6.3 g, 
0.03 mol) in 500 mL water. The resulting slurry was heated, with stirring, 
to and held at 60.degree. C. for three hours. The slurry was cooled to 
room temperature with stirring and then filtered and washed on the filter 
with water. The solid material collected was dried on a steam bath and 
then calcined in air for one hour at 200.degree. C., one hour at 
350.degree. C. and three hours at 550.degree. C. The catalyst composition 
thus obtained contained 9.4 weight percent copper, had a BET surface area 
of 12.4 m.sup.2 /g and had the formula Cu.sub.0.12 Ti.sub.0.88 O.sub.1.88. 
Example 3 
Example 2 was repeated using 4.34 g (0.024 mol) of cupric acetate to obtain 
a catalyst composition containing 6.6 weight percent copper. The catalyst 
had a BET surface area of 11.7 m.sup.2 /g and the formula Cu.sub.0.08 
Ti.sub.0.92 O.sub.1.92. 
Example 4 
Example 2 was repeated using 3.14 g (0.017 mol) cupric acetate to obtain a 
catalyst composition containing 5.0 weight percent copper. The catalyst 
had a BET surface area of 7.7 m.sup.2 /g and the formula Cu.sub.0.06 
Ti.sub.0.94 O.sub.1.94. 
Example 5 
Example 2 was repeated using 1.89 g (0.010 mol) of cupric acetate to obtain 
a catalyst composition containing 3.1 weight percent copper. The catalyst 
had a BET surface area of 13.6 m.sup.2 /g and the formula Cu.sub.0.04 
Ti.sub.0.96 O.sub.1.96. 
Example 6 
Example 2 was repeated using 0.63 g (0.003 mol) of cupric acetate to obtain 
a catalyst composition containing 1.1 weight percent copper. The catalyst 
had a BET surface area of 11.8 m.sup.2 /g and the formula Cu.sub.0.02 
Ti.sub.0.98 O.sub.1.98. 
Example 7 
To 100 g silica (Davison 59) was added a solution of 71.2 g titanium 
tetraisopropoxide in 300 mL of 2-propanol. The mixture was stirred and 
heated at 60.degree. C. until all of the 2-propanol was removed. To the 
resulting solid was added over 10 minutes a solution of 37.7 g cupric 
acetate in 800 mL of 60.degree. C. water. The mixture was stirred and 
evaporated to dryness on a steam bath and the solid obtained was calcined 
for one hour at 200.degree. C., for one hour at 350.degree. C. and for 
three hours at 550.degree. C. to give a black catalyst. The catalyst 
composition contained 34 weight percent copper, had a BET surface area of 
222 m.sup.2 /g and consisted of Cu.sub.0.43 Ti.sub.0.57 O.sub.1.57 coated 
on silica. 
Example 8 
A mixture of 51.2 g silica (Davidson Grade 59) and 106.8 g titanium 
tetraisopropoxide was heated on a steam bath for one hour with stirring to 
give a white solid to which was added a solution of 47.13 g of cupric 
acetate monohydrate in 1 L of 60.degree. C. water. The resulting slurry 
was evaporated to dryness and calcined according to the procedure 
described in Example 7. The catalyst composition thus obtained was a 
brown-black, contained 31 weight percent copper, had a BET surface area of 
183 m.sup.2 /g and consisted of Cu.sub.0.39 Ti.sub.0.61 O.sub.1.61 coated 
on silica. 
Example 9 
To a solution of 34.5 g cupric acetate monohydrate and 8.5 g lanthanum 
acetate.cndot.11/2H.sub.2 O in 2 L water was added in two minutes 356 g 
titanium tetraisopropoxide. The slurry was stirred for 30 minutes and the 
pH adjusted to 7.0 with concentrated ammonium hydroxide. The slurry then 
was heated, with stirring, to and held at 60.degree. C. for 90 minutes and 
cooled to 25.degree. C. in two hours. The slurry then was filtered and the 
green solid collected was dried on a steam bath in air followed by 
calcining according to the procedure described in Example 7. The dark 
brown-black catalyst composition contained 9.3 weight percent copper and 
2.9 weight percent lanthanum, had a BET surface area of 51.9 m.sup.2 /g 
and consisted of La.sub.0.02 Cu.sub.0.12 Ti.sub.0.86 O.sub.1.87. 
Example 10 
To a solution of 59.52 g cupric acetate monohydrate and 4.25 g lanthanum 
acetate .cndot.11/2H.sub.2 O in 1 L water was added in five minutes 176 g 
titanium tetraisopropoxide. The mixture was cooled to 25.degree. C. with 
stirring and the pH adjusted to 7.0 with concentrated ammonium hydroxide. 
The slurry then was filtered and the green solid collected was dried on a 
steam bath in air followed by calcining according to the procedure 
described in Example 7. The black catalyst composition contained 23.7 
weight percent copper and 2.3 weight percent lanthanum, had a BET surface 
area of 13.1 m.sup.2 /g and consisted of La.sub.0.02 Cu.sub.0.03 
Ti.sub.0.68 O.sub.1.69. 
Example 11 
Titanium tetraisopropoxide (44.5 g) was added in five minutes to 300 mL 
water and the resulting slurry was stirred for ten minutes and heated to 
60.degree. C. To the slurry was added 53.6 g powdered cupric acetate 
monohydrate and the mixture was stirred at 60.degree. C. while the pH was 
adjusted to 10.0 with concentrated ammonium hydroxide. The mixture was 
stirred for 15 minutes at 60.degree. C. and then evaporated to dryness. 
The solid obtained was calcined as described in Example 7 to give a black 
catalyst composition containing 50.4 weight percent copper and having the 
formula Cu.sub.0.63 Ti.sub.0.37 O.sub.1.37. 
Example 12 
Titanium tetraisopropoxide (26.6) was added to 300 mL water in fifteen 
minutes and the slurry was stirred for one hour. The solids were filtered 
off, reslurried in 300 mL water, filtered again and then reslurried in 300 
mL water. After the pH was adjusted to 10.0, the slurry was stirred and 
heated at 60.degree. C. for three hours, then cooled to 25.degree. C. and 
filtered. The solids collected were added to a solution of 31.42 g cupric 
acetate in 500 mL water. The mixture was heated to 60.degree. C. and 
stirred at that temperature for three hours. The mixture was then cooled 
to 25.degree. C., filtered and the solids obtained were washed with 50 mL 
water. The solid material was dried and calcined according to the 
procedure described in Example 7. The black catalyst composition thus 
obtained contained 25.2 weight percent copper, had a BET surface area of 
6.3 m.sup.2 /g and had the formula Cu.sub.0.32 Ti.sub.0.68 O.sub.1.68. 
Example 13 
Example 2 was repeated using 356 g of titanium isopropoxide and 34.5 g 
(0.024 mol) of cupric acetate to obtain a catalyst composition containing 
9.6 weight percent copper. This catalyst had a BET surface area of 11.3 
m.sup.2 /g and the formula Cu.sub.0.12 Ti.sub.0.88 O.sub.1.88. 
Example 14 
Calcium acetate (0.42 g, 0.002 mol) was dissolved in 10 mL of water. To 
this solution was added 5.0 g of the catalyst of Example 13 with stirring. 
This slurry was stirred at 60.degree. C. for five minutes and then was 
evaporated to dryness on a steam bath. The solids obtained were calcined 
in air at 300.degree. C. for three hours. The catalyst thus obtained had a 
surface area of 11.2 m.sup.2 /g. 
Example 15 
Example 14 was repeated using magnesium acetate (0.85 g, 0.004 mol) instead 
of calcium acetate. The resulting catalyst had a surface area of 10.3 
m.sup.2 /g. 
Example 16 
Example 14 was repeated using potassium acetate (0.24 g, 0.002 mol) instead 
of calcium acetate. The resulting catalyst had a surface area of 10.0 
m.sup.2 /g. 
Example 17 
Example 14 was repeated using lanthanum acetate (0.29 g, 0.001 mol) instead 
of calcium acetate. The resulting catalyst had a surface area of 12.0 
m.sup.2 /g. 
Example 18 
To 20.0 g of silica (Davison Grade 57) was added 41.6 g (0.15 mol) titanium 
tetraisopropoxide. The resulting slurry was heated on a steam bath to give 
a white solid. A solution to 13.42 g (0.07 mol) of cupric acetate in 500 
mL of 60.degree. C. water was added to the solid and the mixture was 
evaporated to dryness on a steam bath. The solid was calcined for one hour 
at 200.degree. C., one hour at 250.degree. C. and three hours at 
550.degree. C. The resulting catalyst had a surface area of 182 m.sup.2 /g 
and consisted of Cu.sub.0.31 Ti.sub.0.69 O.sub.1.69. 
Example 19 
The procedure described in Example 18 was repeated using 51.2 g of silica 
(Davison Grade 57), 106.8 g (0.38 mol) of titanium tetraisopropoxide and 
47.13 g (0.24 mol) of cupric acetate. This procedure was performed five 
times and the resulting calcined solids were combined to give a large 
batch of material. This catalyst had a surface area of 186 m.sup.2 /g and 
consisted of Cu.sub.0.39 Ti.sub.0.61 O.sub.1.61. 
HYDROGENATION OF ESTERS 
Example 20-25 describe the liquid phase hydrogenation of dimethyl succinate 
(10.0 g) in methanol (100 mL) in the presence of one of the catalysts 
perpared as described hereinabove. The hydrogenations were conducted in an 
autoclave equipped with a 300 mL glass liner, a stir fin, thermometer, 
pressure gauge, a gas inlet tube and means of heating and cooling the 
autoclave. In each hydrogenation procedure, the methanol, dimethyl 
succinate and the chemically-mixed, copper-titanium oxide catalyst were 
charged to the glass liner which was positioned within the autoclave. The 
autoclave was first pressurized to 500 psi with nitrogen and vented and 
then pressurized to 2000 psi with hydrogen. Stirring was started and the 
autoclave was heated to 200.degree. C. (Example 20) or 300.degree. C. 
(Example 21-25) at the maximum heating rate. The contents of the autoclave 
were stirred at 200.degree. C. (Example 20) or 300.degree. C. (Examples 
21-25) and 2000 psi for five hours and then the autoclave was cooled and 
vented carefully to avoid the loss of any of the contents. 
Example 20 
Using the above-described procedure, dimethyl succinate was hydrogenated at 
2000 psi hydrogen and 200.degree. C. for five hours in the presence of 1.0 
g of the catalyst obtained in Example 1. Analysis of the reaction mixture 
obtained showed 2.4 percent butyrolactone and 11.2 percent 1,4-butanediol. 
Example 21 
Example 20 was repeated using hydrogenation temperature of 300.degree. C. 
to produce a crude product which contained 10.7 percent butyrolactone and 
23.3 percent 1,4-butanediol. 
Example 22 
Example 21 was repeated using 1.0 g of a catalyst prepared by repeating the 
catalyst synthesis procedure described in Example 1. The resulting 
reaction mixture contained 14.1 percent tetrahydrofuran, 3.2 percent 
butyrolactone and 20.0 percent 1,4-butanediol. 
Example 23 
Example 21 was repeated using 1.0 g of the catalyst perpared in Example 2. 
The resulting reaction mixture contained 13.2 percent tetrahydrofuran, 4.9 
percent butyrolactone and 23.9 percent 1,4-butanediol. 
Example 24 
Example 21 was repeated using 1.0 g of the catalyst prepared as described 
in Example 3. The resulting reaction mixture contained 13.4 percent 
tetrahydrofuran, 4.5 percent butyrolactone and 15.1 percent 
1,4-butanediol. 
Example 25 
Example 21 was repeated using 1.0 g of the catalyst prepared in Example 4. 
The resulting reaction mixture contained 6.3 percent tetrahydrofuran, 5.2 
percent butyrolactone and 10.5 percent 1,4-butanediol. 
Examples 26-68 describe the results obtained from the gas-phase 
hydrogenation of methyl acetate using the catalysts provided by our 
invention and varying gas flow rates, temperatures and pressures. The 
apparatus used consisted of a 1/4-inch interior diameter, stainless steel, 
tubular reactor in which was placed 1 mL (approximately 1 g) of catalyst 
held in place with quartz wool plugs above and below the catalyst bed. The 
central portion of the tube was encased in an electric furance with a 
thermocouple fixed in the catalyst bed. Hydrogen and methyl acetate vapor 
were fed, using Brooks flow controllers, to the top of the reactor in a 
hydrogen:methyl acetate mole ratio of 3:1 and 6:1. The pressure of the 
off-gas removed from the bottom of the reactor was reduced to atmospheric 
pressure, cooled in a glycol condenser system and the resulting liquid and 
gas phases were analyzed by gas chromatography. The results obtained in 
Examples 26-68 are given in the Table. The numerical designation for the 
catalyst (Cat) used in each example refers to the example which describes 
its preparation. Temperature (Temp) and total pressure (Press) are given 
in .degree.C. and pounds per square inch absolute, respectively. Gas flow 
rates are given as the gas hourly space velocity (GHSV) which is the mL of 
gas fed per hour divided by the mL of catalyst bed. The % methyl acetate 
(MeOAc) designates the mole percent of methl acetate which is not 
converted to other commpounds. The conversion rates to methanol (MeOH), 
ethanol (EtOH) and ethyl acetate (EtOAc) are given in micromoles per g 
catalyst per second. 
TABLE 
__________________________________________________________________________ 
Rate of Conversion to 
Ex. 
Cat. 
Temp. 
Press 
GHSV 
% MeOAc 
MeOH EtOH 
EtOAc 
__________________________________________________________________________ 
26 1 231 740 
32067 
60.5 3.1 1.4 2 
27 1 251 775 
32067 
42.2 4.9 2.1 2.8 
28 1 278 775 
32067 
56 10 4.3 5.1 
29 1 297 800 
29343 
44.8 8.2 2.8 5.2 
30 1 306 780 
29343 
9.2 8 3 5.4 
31 1 306 800 
28256 
45.77 7.99 3.06 
5.1 
32 1 288 765 
25660 
57.9 11.8 6.4 3.9 
33 13 247 760 
28784 
25.6 4.6 1.6 2 
34 13 276 765 
28502 
34.4 10.5 4.9 4.8 
35 7 278 770 
28226 
36.6 27.9 8.7 12.2 
36 12 246 790 
28179 
23 5.8 3 2 
37 12 277 830 
28226 
39.3 18.4 9.1 6.1 
38 12 303 815 
28502 
50.6 28.7 16.2 
8.4 
39 12 242 780 
16350 
46.8 10.8 7.8 3.6 
40 12 279 790 
16632 
32.2 17.4 7.3 6.7 
41 5 245 800 
28502 
22.1 3.8 1.4 1.7 
42 5 270 790 
28502 
33.8 8.3 3.3 3.9 
43 9 249 760 
28502 
42.5 13.5 5.7 5.5 
44 9 287 760 
28502 
69.4 31.3 21.4 
7.7 
45 8 252 745 
28226 
35.5 22.6 7 10.6 
46 8 287 725 
28502 
60.7 56.3 33.8 
16 
47 10 247 810 
28824 
41.8 6.1 4 5.4 
48 10 283 800 
28224 
80.7 23.1 32.5 
9 
49 18 263 765 
27942 
54.8 11.8 8.3 11.3 
50 18 292 750 
27942 
72.8 22.3 27.9 
12.7 
51 18 274 795 
16074 
50 12.9 10.7 
14.2 
52 14 249 770 
27942 
30 1.8 1.4 1.3 
53 14 275 775 
28224 
45.9 3.8 3 3.9 
54 17 248 750 
27102 
47.4 1.8 0.8 0.5 
55 17 292 750 
27104 
61.2 10.4 6.4 2.5 
56 19 248 750 
27384 
39 10.5 2.8 4.4 
57 19 281 760 
27384 
58.9 24.9 13.9 
6.8 
58 19 252 760 
14676 
33.6 10.5 2.7 4 
59 19 280 750 
14952 
38.2 23.5 10.3 
7.7 
60 15 242 750 
27384 
27.5 1.4 0.9 0.1 
61 15 279 750 
27384 
35.5 6.3 3.6 1.7 
62 15 280 740 
15234 
26.2 3.4 1.9 0.8 
63 16 244 750 
27384 
21 0.7 0.2 0.1 
64 16 280 760 
27384 
19.3 1.1 0.6 0.1 
65 16 295 750 
15234 
22.5 1.6 1 0.1 
66 14 247 740 
27384 
28.4 3.5 1.7 1 
67 14 283 740 
27384 
50.3 13.2 8.1 3.4 
68 14 276 740 
15234 
36.9 9 4.4 2.6 
__________________________________________________________________________ 
The invention has been described in detail with particular reference to 
preferred embodiments thereof, but it will be understood that variations 
and modifications will be effected within the spirit and scope of the 
invention.