Production of 1,7-octadiene from butadiene

In the process for preparing 1,7-octadiene by hydrodimerizing butadiene in the presence of a solubilized palladium or palladium compound, a tertiary phosphine, formic acid, a base and optionally a solvent, improved rates of conversions of butadiene to 1,7-octadiene are obtained by carrying out the process in the presence of supported palladium, platinum or rhodium.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to the production of 1,7-octadiene by 
hydrodimerizing butadiene. 
2. Description of the Prior Art 
Linear dimerization of butadiene provides a source of C.sub.8 unsaturated 
hydrocarbon intermediates useful for the synthesis of diacids, diesters, 
diols or diamines. A particularly preferred dimer is 1,7-octadiene which 
has terminal double bonds and allows the production of product having only 
terminal functional groups. 
Wright in U.S. Pat. No. 3,732,328, issued May 8, 1973, prepares mixtures of 
octadienes by reacting butadiene in the presence of a palladium compound, 
a polar solvent, a reducing agent and a tertiary phosphine. 
Wright in U.S. Pat. No. 3,823,199, issued July 9, 1974, prepares mixtures 
of octadienes by reacting butadienes in the presence of palladium metal or 
a palladium compound, a non-polar solvent, a reducing agent and a tertiary 
phosphine. 
Wright in British Pat. No. 1,341,324 issued Dec. 9, 1973 discloses 
processes similar to above but uses amine solvents. 
Gardner et al, Tetrahedron Letters No. 2, pp. 163-164 discloses the 
production of mixtures of octadienes by reacting butadiene in the presence 
of palladium salts, an organic base, formic acid and a phosphine. 
Roffia et al, Journal of Organometallic Chemistry, 55 (1973) 405-407 
utilizes a triphenyl phosphine-zero valent palladium complex catalyst in 
benzene in the presence of formic acid to dimerize butadiene. Although 
Roffia et al reported a 75% butadiene conversion, only 22% of the product 
was 1,7-octadiene. 
None of the references cited above have disclosed the concept of increasing 
the rate of formation of 1,7-octadiene by also using a supported 
palladium, platinum and/or rhodium catalyst in conjunction with 
solubilized palladium catalyst. Increased rates are important to 
commercial ventures. High selectivities and conversions at low rates can 
make a venture unprofitable. The instant invention provides significantly 
enhanced rates over those of the prior art. 
SUMMARY OF THE INVENTION 
The process of this invention is directed to the hydrodimerization of 
butadiene to 1,7-octadiene at high rates by reacting the butadiene in the 
presence of solubilized palladium or a solubilized palladium compound, 
formic acid, a base, optionally a solvent, a tertiary phosphine and a 
supported palladium, platinum or rhodium catalyst. The addition of the 
supported catalyst to the solubilized palladium tertiary phosphine complex 
conventionally utilized provides for a significant increase in the rate of 
conversion of butadiene to 1,7-octadiene as compared to rates utilizing 
solubilized palladium alone or supported palladium alone. 
DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Solvents are not essential to the process of this invention, but a good 
organic solvent can promote the rate of reaction by a factor of two or 
more. 
Wright in above-cited U.S. Pat. No. 3,823,199 cites the use of non-polar 
solvents such as paraffinic, cycloparaffinic or aromatic which are useful 
in the process of this invention. The solvent can be a paraffin or 
cycloparaffin containing 5 to 16 carbon atoms, such as hexane, dodecane, 
pentadecane, cyclohexane, methylcyclohexane and the like. Suitable 
solvents also include aromatic hydrocarbons such as benzene, lower alkyl 
substituted aromatic hydrocarbons such as toluene, m-, p- and o-xylene, 
halogenated aromatic hydrocarbons including chloro, bromo and iodo 
substituted, such as chlorobenzene and the like. Halogenated lower 
aliphatic compounds such as chloroform, methylene chloride, carbon 
tetrachloride and the like may be used, in particular chloroform is 
preferred. 
Further useful are the amine solvents cited by Wright in above-noted 
British Pat. No. 1,341,324. A wide range of amines are useful provided 
that they are liquid under reaction conditions. Tertiary amines are 
preferred to primary and secondary amines. Suitable amine solvents include 
alkylamines, cycloalkylamines, arylamines and heterocyclic amines such as 
morpholine, pyridine, piperazine and piperidine. Examples of these classes 
of amines are the lower alkylamines containing 2 to 6 carbon atoms in each 
alkyl group such as triethylamine; monocyclohexylamine, and 
N-alkyl-cyclo-hexylamines containing up to 12 carbon atoms; aniline and 
N-alkylanilines containing up to 12 carbon atoms and N-alkylmorpholines 
containing up to 12 carbon atoms. 
Preferred solvents are those of moderate coordinating ability, and which 
include nitriles such as lower alkyl nitriles, hydrocarbon aromatic 
nitriles including acetonitrile, benzonitrile and the like, amides 
including benzamide, acetamide, mono- and di-substituted amides where the 
substituent is preferably lower alkyl. Suitable substituted amides include 
N-methyl acetamide, N,N dimethyl acetamide and dimethylformamide. Dialkyl 
sulfoxides such as dimethyl sulfoxide and sulfones such as sulfolane and 
alkyl-substituted sulfolane are satisfactory. Simple ethers such as the 
dilower alkyl ethers including dimethyl ether, diethylether, and the like 
function satisfactorily. Hydrocarbon aromatic ethers such as the lower 
alkyl phenyl ethers may also be used, and include methyl phenyl ether 
(anisole), ethyl phenyl ether (phenetole) and the like. Cyclic, saturated 
hydrocarbon ethers such as tetrahydrofuran, tetrahydropyran and the like 
are also suitable solvents. Lower alkyl diethers such as dimethoxy ethane, 
and the like may be used. In addition, the cyclic diethers such as 
1,4-dioxane are also suitable solvents. 
Simple lower alkyl esters of lower alkanoic acids such as ethyl acetate, 
methyl acetate, methyl butyrate and the like as well as cyclic diesters 
such as ethylene carbonate are also suitable solvents of moderate 
coordinating ability. Ketones, including lower aliphatic ketones such as 
methyl ethyl ketone and hydrocarbon aromatic ketones such as acetophenone 
are also satisfactory solvents. Lower mono- and di-alkanols such as 
isopropanol, ethylene glycol and the like may be used if desired. The 
preferred solvents of moderate coordinating ability include nitriles, 
formamides, such as dimethylformamide, dilower alkyl ethers, lower alkyl 
phenyl ethers, simple lower alkyl esters of lower alkanoic acids, ketones 
and lower alkanols. 
The particularly preferred solvents utilized in this invention include 
benzene, dimethylformamide, chlorobenzene, anisole, N,N-dimethylacetamide, 
nitromethane, ethyl acetate, isopropanol, benzonitrile, chloroform, methyl 
ethyl ketone, acetonitrile, diethylether, acetophenone, toluene, ethylene 
glycol, ethylene carbonate, propylene carbonate and sulfolane. 
Particularly desired solvents are nitromethane, ethylene carbonate and 
propylene carbonate. 
The preferred organic solvents will have carbon numbers ranging from 1 to 
about 20. Particularly desired solvents are those which give two-phase 
systems which allow easy product separation such as, for example, 
nitromethane, ethylene carbonate and propylene carbonate. 
The amount of solvent added should be sufficient to dissolve the palladium 
compound-tertiary phosphine complex. 
The formic acid is utilized as a source of hydrogen for the process. It is 
present in the reaction mixture as a salt of the base promoter utilized. 
It is thought that dissociation of the formic acid-base salt provides a 
suitable amount of formic acid necessary to provide the required hydrogen. 
Excess free acid present in the reaction mixture has an inhibitory effect 
on the reaction. 
It is desirable that some formic acid, as the salt, be present during the 
entire course of the reaction. When operating the process batch-wise, this 
can be accomplished by adding a stoichiometric amount of formic acid 
initially, 1 mole of formic acid for every 2 moles of butadiene, or by 
continuously or periodically adding additional amounts of formic acid. It 
is essential, however, that the ratio of base to formic acid present in 
the reaction medium never be less than 1. 
The base must be one which can neutralize formic acid according to the 
reaction: 
EQU HCOOH+B.fwdarw.HCOO.sup.- HB.sup.+. 
The base may be either insoluble or soluble in the reaction medium. 
The base may be organic or inorganic. Suitable organic bases typically have 
dissociation constants greater than 10.sup.-8 and include tertiary amine 
such as triethylamine, tributyl amine, dimethylethyl amine, lutidine, 
tripropyl amine, N-methyl morpholine, isoquinoline. 
N-methyl-2,2,6,6-tetramethyl piperidine, 2,8-(dimethylamine)naphthalene 
and the like. 
Suitable inorganic bases include ammonia, the hydroxide bases such as 
sodium hydroxide, potassium hydroxide, calcium hydroxide; ammonium 
hydroxide; the carbonates and bicarbonates such as sodium carbonate, 
sodium bicarbonate, potassium carbonate, potassium bicarbonate, calcium 
carbonate and the like; the weak bases such as sodium acetate, potassium 
acetate, ammonium carbonate, ammonium acetate and the like. When the 
inorganic bases are utilized, small amounts of water may be present. 
The mole ratio of base to formic acid must be at least equal to 1. When 
organic bases are utilized, excess base may be utilized as a solvent or 
the amine-base salt may be used as the solvent. 
The conventional catalyst used in the process of this invention is 
palladium or a palladium compound complexed with a tertiary phosphine 
ligand. The palladium may be in any of its possible valence states, e.g. 
0, +2, etc. Suitable palladium compounds include the palladium 
carboxylates, particularly palladium carboxylates derived from alkanoic 
acids containing up to six carbon atoms such as palladium acetate, 
complexes such as palladium acetylacetonate, bisbenzonitrile palladium 
(II) and lithium palladous chloride as well as the palladium halides, 
nitrates and sulfates such as palladous chloride and palladium nitrate 
(Pd(NO.sub.3).sub.2 (OH).sub.2) and palladium sulfate. Suitable 
palladium-phosphine complexes are Pd(R.sub.3 P).sub.2 and Pd(R.sub.3 
P).sub.3. The solubilized palladium is present in the reaction mixture in 
catalytic amounts; preferably from about 10.sup.-1 to 10.sup.-6 and most 
preferably from about 10.sup.-2 to about 10.sup.-5 molar. 
Any tertiary phosphine which can be dissolved in the reaction solvent may 
be used. The bisphosphines, such as 1,3-bisphenylphosphinopropane and 
1,4-bisdiphenylphosphineobutane, will not function in the present 
invention as the tertiary phosphine, the butadiene conversions obtained 
are unsatisfactory. Accordingly, it is preferred to use a mono-phosphine. 
Suitable phosphines are represented by the formula: 
##STR1## 
wherein R.sub.a, R.sub.b and R.sub.c may be the same or different and are 
selected from aryl such as phenyl, p-tolyl, o-tolyl, m-tolyl, 
p-chlorophenyl, phenoxy, p-methylphenoxy, p-anisoly, m-anisoyl and the 
like, alkyl of 1 to 8 carbon atoms, preferably 1 to 5 carbon atoms, alkoxy 
having from 1 to 8 carbon atoms, but preferably from 1 to 3 carbon atoms. 
Preferably, R.sub.a, R.sub.b and R.sub.c represent aryl, alkyl, or a 
mixture thereof. The more preferred tertiary phosphines, are the triaryl 
and trialkyl phosphines. The most preferred tertiary phosphines have the 
general formula: 
EQU R.sub.1 R.sub.2 R.sub.3 P 
wherein R.sub.1 is benzyl or branched alkyl, aralkyl, alkenyl, and 
cycloalkyl having from 3 to about 10 carbon atoms with branching occuring 
at a carbon atom no more than two carbon atoms from the phosphorus atom 
and R.sub.2 and R.sub.3 are R.sub.1 or independently are alkyl, alkenyl or 
aryl having from 1 to about 10 carbon atoms. 
Illustrative of the R.sub.1 moiety are, for alkyl, isopropyl, sec-butyl, 
tert-butyl, isobutyl, neopentyl, sec-pentyl, tert-pentyl, 2-methylbutyl, 
sec-hexyl, tert-hexyl, 2,2-dimethylpropyl; for aryalkyl, 
alpha-methylbenzyl, alpha, alpha-dimethylbenzyl, 
alpha-methyl-alpha-ethylbenzyl, phenylethyl, phenylisopropyl, 
phenyl-tert-butyl; for alkenyl, allyl, crotyl, methallyl, 1-methylethenyl, 
1-methyl-2-propenyl, 1,1-dimethyl-2-propenyl, 1-methyl-3-butenyl; and, for 
cycloalkyl, cyclopropyl, cyclobutyl, cyclo-pentyl, cyclohexyl, cycloheptly 
cycloalkyl and the like. 
Illustrative of the R.sub.2 and R.sub.3 are, for example, methyl, ethyl, 
propyl, butyl, pentyl, hexyl, octyl, nonyl and decyl for alkyl; allyl, 
crotyl and methallyl for alkenyl, and phenyl, tolyl, xylyl, ethylphenyl, 
propylphenyl for aryl. Two or more of the instant phosphines may be used 
in the same reaction or another phosphine may be replaced by reacting in 
situ one of the instant phosphines. The mole ratio of tertiary phosphine 
to palladium is at least 1. Preferably the mole ratio of phosphine to 
palladium ranges from about 1:1 to about 1:20 and preferably from about 
2:1 to about 5:1. The use of the phosphines of the invention provides 
extremely high selectivities to 1,7-octadiene. 
The promotive supported co-catalyst of the invention comprises a metal 
selected from the group consisting of palladium, platinum, rhodium or 
mixtures thereof supported on an inert support. The support employed in 
these co-catalysts in its broadest aspects is selected from the large 
number of conventional, porous catalyst carriers or supports materials 
which are essentially inert under reaction conditions. Such conventional 
materials may be of natural or synthetic origin. Very suitable supports 
comprise those of siliceous, aluminous, and carbonaceous compositions. 
Specific examples of suitable supports are the alumina oxides (including 
the materials sold under the trade name "alundum"), charcoal, activated 
carbon, pumice, magnesia, zirconia, kieselguhr, fuller's earth, silicon 
carbide, calcium carbonate, porous agglomerates comprising silicon and/or 
silicon carbide, silica, mullite, selected days, artificial and natural 
zeolites and ceramics. Preferred supports are the aluminas, the silicas, 
and the carbons such as activated charcoal and graphite. 
The co-catalysts are prepared in a conventional manner by impregnating the 
support with a solution of a suitable metal compound, and then heating the 
impregnated support in a reducing environment to reduce the metal compound 
to the metal. 
Suitable impregnating solutions are made, for example, from metal 
carboxylates such as acetates, halides, nitrates, sulfates and the like. 
Typical examples are aqueous solutions of palladous chloride, palladous 
nitrate, palladous acetate, platinium chloride chloroplatininc acid, 
rhodium nitrate and the like. 
The co-catalysts utilized in the invention are not novel per se and find 
use today in many industries, especially the petrochemical industries, for 
the hydrogenation and dehydrogenation of organic compounds. The supported 
metal catalysts are readily available commercially. 
Catalysts according to this invention preferably contain from about 0.0001 
to about 30, more preferably from about 0.001 to about 10 and most 
preferably from about 0.001 to about 1 percent by weight of metal based on 
the total weight of the catalyst. The use of larger amounts of catalytic 
metal is not excluded but is generally uneconomic due to the high price of 
the metals. 
The ratio of the metal in the supported catalyst to the solubilized 
palladium ranges from about 0.001 to about 10 preferably from about 0.001 
to about 3, and more preferably from about 0.001 to about 1. 
The supported co-catalyst may be used in bulk or powdered form. The 
powdered form (less than about 100 mesh) is useful in a batch reaction 
utilizing a homogeneous conventional palladium-phosphine complex catalyst. 
In continuous processes the co-catalyst may be used as pellets, rings or 
the like in a fixed bed in conjunction with a homogeneous conventional 
palladium-phosphine complex catalyst or may be admixed in a fixed bed with 
a heterogeneous palladium phosphinated resin complex. 
The addition of carbon dioxide to the reaction system has been found to 
increase the extent of butadiene conversion, but does not affect the 
selectivity. When it is desired to use carbon dioxide to increase the 
conversion rate, the partial pressure of the CO.sub.2 in the reaction 
system may be from about 10 to about 100 psia. Since carbon dioxide is a 
by-product of the process, it is possible to generate sufficient carbon 
dioxide in situ to enhance the conversion rates. 
The process can be either continuous or batch. The reaction temperature of 
the process is not critical, however, it is preferred to maintain the 
reaction between about 0.degree. to about 100.degree. C. preferably 
between about 20.degree. to about 70.degree. C. The process is conducted 
under a sufficient pressure to maintain liquid phase conditions at the 
reaction temperature. Typically the pressure is autogeneous. 
The process of this invention is particularly useful when applied to a BBB 
stream from an oil pyrolysis unit. These BBB streams are the C.sub.4 cut 
from a thermal cracking unit typically containing 30-40% butadiene, 20-35% 
isobutene and 20-30% n-butenes and many minor components including about 
1/2% of vinylacetylene. Vinyl acetylene is a moderate retarder for 
butadiene hydrodimerization. The addition of from about 0.2 to about 4 
percent by volume of hydrogen along with the supported metal co-catalyst 
of this invention of the BBB hydrodimerization system eliminates the 
retardation, presumably by hydrogenating the vinylacetylene. 
The invention is thus a process for preparing 1,7-octadiene by 
hydrodimerizing 1,3-butadiene which comprises contacting the 1,3-butadiene 
with (a) a solubilized palladium catalyst, (b) a supported metal 
co-catalyst selected from the group consisting of palladium, platinum, 
rhodium and mixtures thereof wherein the metal is present on the carrier 
in amounts ranging from about 0.001 to about 30, preferably 0.001 to about 
10 percent by weight of the total supported catalyst and the ratio of the 
metal in the supported catalyst to the solubilized palladium ranges from 
about 0.001 to about 10, preferably from about 0.001 to about 3 and more 
preferaby from about 0.001 to about 1, (c) a tertiary phosphine (d) a base 
and (e) optionally a solvent. The temperature of the process ranges from 
about 0.degree. C. to about 100.degree. C., the solubilized palladium 
ranges from about 10.sup.-1 to about 10.sup.-6 molar, the mole ratio of 
tertiary phosphine to solubilized palladium is at least 1 and the molar 
ratio of base to formic acid is at least 1. The carrier is preferaby 
siliceous, aluminous or carbonaceous.

The process of this invention will be further described by the following 
illustrative embodiments which are provided for illustration and are not 
to be construed as limiting the invention. 
ILLUSTRATIVE EMBODIMENTS 
Illustrative Embodiment I 
To an 80 milliliter glass-lined autoclave were charged 2.7.times.10.sup.-5 
moles of palladium as a 10% water solution of Pd(NO.sub.3).sub.2 
(OH).sub.2, 5.4.times.10.sup.-5 moles (isopropyl).sub.3 phosphine, 2.5 
grams of triethylamine formic acid salt, 10 milliliters of pyridine and 2 
grams of 1,3-butadiene. The stirred reactor was heated to 45.degree. C. 
for 1 hour, cooled and the product was analyzed by gas chromatography for 
the amount of 1,7-octadiene present. This case provided the base case for 
solubilized palladium alone and is shown in Table I as example I. In this 
base case, the soluble palladium catalyst is present at a concentration of 
about 1.8.times.10.sup.-3 molar. 
The above experiment was repeated four additional times using 0.0001 g, 
0.001 g, 0.01 g and 0.1 g of 10% w palladium on carbon catalyst (Baker and 
Co., Inc.) in addition to the solubilized catalyst present at a 
concentration of 1.8.times.10.sup.-3 molar. The results are shown in Table 
I as examples 2-5. Column 4 of the Table gives the average rate (R) of 
formation of 1,7-octadiene in the product per hour. Column 5 reports the 
percentage of the butadiene reactant originally present in the reaction 
which is converted to the desired 1,7-octadiene product in one hour 
reaction time. In cases where the conversion to 1,7-octadiene was between 
5 and 95% in one hour reaction time, the selectivity to 1,7-octadiene was 
about 98%. Column 6 is the rate (R) normalized to the rate obtained using 
solubilized palladium alone (R.sub.o), and column 7 gives the ratio of 
supported palladium to solubilized palladium. 
TABLE I 
__________________________________________________________________________ 
Rate, % w 
% of Butadiene 
1,7-Octadiene 
Reactant Converted 
Supported 
Moles of Palladium Added 
In Product 
to 1,7-Octadiene 
Normalized 
Pd/Solubil- 
Example 
Solubilized 
Supported 
Per Hour 
In 1 Hour Rate R R.sub.o 
ized Pd 
__________________________________________________________________________ 
1 2.7 .times. 10.sup.-5 
None 5.87 34.5 1.0 -- 
2 2.7 .times. 10.sup.-5 
9.4 .times. 10.sup.-8 
8.5 50 1.4 0.0035 
3 2.7 .times. 10.sup.-5 
9.4 .times. 10.sup.-7 
16.0 94 2.7 0.035 
4 2.7 .times. 10.sup.-5 
9.4 .times. 10.sup.-6 
10.9 64 1.9 0.35 
5 2.7 .times. 10.sup.-5 
9.4 .times. 10.sup.-5 
5.84 34.2 1.0 3.5 
6 None 9.4 .times. 10.sup.-7 
0.04 0.24 -- -- 
7 None 9.4 .times. 10.sup.-6 
0.33 1.9 -- -- 
8 None 9.4 .times. 10.sup.-5 
2.28 13.4 -- -- 
__________________________________________________________________________ 
Examples 6-8 are repeats of the above experiments using only supported 
palladium alone. 
To an 80 milliliter glass-lined autoclave were charged 2.7.times.10.sup.-5 
moles of palladium as a 10% water solution of Pd(NO.sub.3).sub.2 
(OH).sub.2, 5.4.times.10.sup.-5 moles (isopropyl).sub.3 phosphine, 2.5 
grams of triethylamine formic acid salt, 10 milliliters of pyridine and 2 
grams of 1,3-butadiene (concentration of soluble palladium being about 
1.8.times.10.sup.-3 molar) and the appropriate supported metal co-catalyst 
from Table II. The stirred reactor was heated to 45.degree. C. for 1 hour, 
cooled and the product was analyzed by gas chromatography for the amount 
of 1,7-octadiene present. The results are shown in Table II. All powders 
used were less than 100 mesh. 
TABLE II 
______________________________________ 
Rate, % w, 
% of Buta- 
1,7-Octa- diene Reactant 
Moles of diene In Converted to 
Supported Supported Product 1,7-Octadiene 
Metal Co--Catalyst 
Pd Per Hour In 1 Hour 
______________________________________ 
None -- 5.87 34.5 
.sup.(1) 0.05 g of 0.2% Pd/C 
9.4 .times. 10.sup.-7 
10.0 58.8 
.sup.(3) 0.01 g of 10% 
9.4 .times. 10.sup.-7 
14.07 83 
Pd/Al.sub.2 O.sub.3 
.sup.(4) 0.02 g of 5% 
9.4 .times. 10.sup.-6 
13.25 78 
Pd/Al.sub.2 O.sub.3 
.sup.(5) 0.02 g of 5% 
9.4 .times. 10.sup.-6 
9.58 56.3 
Pd/CaCO.sub.3 
.sup.(6) 0.1 g of 1% Pt/C 
9.4 .times. 10.sup.-6 
7.79 45.8 
.sup.(7) 0.02 g of 5% 
9.4 .times. 10.sup.-6 
9.41 55.4 
Rh/Al.sub.2 O.sub.3 
.sup.(8) 0.02 g of 5% Ru/C 
9.4 .times. 10.sup.-6 
5.0 29.5 
.sup.(9) 0.1 g of 10% Ni/C 
9.4 .times. 10.sup.-5 
5.35 31.5 
.sup.(9) 0.01 g of 10% Co/C 
9.4 .times. 10.sup.-6 
5.59 33 
.sup.(9) 0.01 g of 10% Fe/C 
9.4 .times. 10.sup.-6 
5.92 35 
______________________________________ 
.sup.(1) 0.2% Pd/Charcoal Matheson, Coleman & Bell 
.sup.(3) 10% PdAl.sub.2 O.sub.3 Engelhard Industries, Inc. 
.sup.(4) 5% Pd/CaCo.sub.3 Engelhard Industries, Inc. 
.sup.(5) 5% Pd/CaCo.sub.3 Engelhard Industries, Inc. 
.sup.(6) 1% Pt/Charcoal Matheson, Coleman & Bell 
.sup.(7) 5% Rh/Al.sub.2 O.sub.3 Engelhard 
.sup.(8) 5% Ru/C Engelhard 
.sup.(9) Union Carbide porous carbon carrier (A &gt; 1000 m.sup.2 /gm) first 
impregnated with metal nitrate solution, dried and then reduced with 
hydrogen at 500.degree. C. 
The above results demonstrate the superiority of supported palladium, 
platinum and rhodium when compared to other supported catalysts. 
Illustrative Embodiment III 
To an 80 ml glass-lined autoclave were charged 2.7.times.10.sup.-5 moles of 
palladium of the appropriate palladium compound listed in Table III, 
5.4.times.10.sup.-5 moles of (isopropyl).sub.3 phosphine, 2.5 g of 
triethylamine-formic acid salt, 10 ml of pyridine and 2 g of 
1,3-butadiene. The stirred reactor was heated to 45.degree. C. for 1 hour, 
cooled and the product was analyzed by gas chromatography for the amount 
of 1,7-octadiene present. The above reaction was repeated adding using 
0.01 g (9.4.times.10.sup.-6 moles) of 10% Pd/C (Baker&lt;100 mesh). In all 
cases, the concentration of soluble palladium catalyst was 
1.8.times.10.sup.-3 molar. The results are shown in Table III. 
TABLE III 
______________________________________ 
% of Buta- 
Rate, % diene Reac- 
1,7- tant Con- 
Octadiene verted to 1,7- 
Pd Salt Co-- In Product 
Octadiene 
Utilized Catalyst Per Hour In 1 Hour 
______________________________________ 
Pd (NO.sub.3).sub.2 (OH).sub.2 
None 5.87 34.5 
(10% aqueous solution) 
Pd (NO.sub.3).sub.2 (OH).sub.2 
None 5.61 33.0 
Pd (acetate).sub.2 
None 0.81 4.8 
Pd (acetylacetonate).sub.2 
None 1.86 10.9 
Pd SO.sub.4 None 0.65 3.8 
Pd Cl.sub.2 None 0.48 2.8 
Pd (NO.sub.3).sub.2 (OH).sub.2 
10% Pd/C 16.0 94 
(10% aqueous solution) 
Pd (NO.sub.3).sub.2 (OH).sub.2 
10% Pd/C 14.67 86.5 
Pd (acetate).sub.2 
10% Pd/C 4.51 26.5 
Pd (acetylacetonate).sub.2 
10% Pd/C 4.10 24.1 
Pd SO.sub.4 10% Pd/C 5.11 30.0 
Pd Cl.sub.2 10% Pd/C 1.48 8.7 
______________________________________ 
The above results show that the rate enhancement effect is shown for a 
number of different solubilized palladium salts. 
Illustrative Embodiment IV 
To an 80 ml glass-lined autoclave were charged 0.9.times.10.sup.-5 moles as 
a 10% water solution of Pd(NO.sub.3).sub.2 (OH).sub.2, 1.8.times.10.sup.-5 
moles (isopropyl).sub.3 phosphine, 2.5 grams of triethylamine formic acid 
salt, 10 milliliters of pyridine and 2 grams of 1,3-butadiene. The stirred 
reactor was heated to 45.degree. C. for 1 hour, cooled and the process was 
analyzed by gas chromatography for the amount of 1,7-octadiene present. 
This case provided the base case for solubilized palladium alone and 
provides one-third the amount of solubilized palladium as does 
Illustrative Embodiment I (the concentration of soluble palladium being 
0.6.times.10.sup.-3 molar in this case versus 1.8.times.10.sup.-3 molar in 
Illustrative Embodiment I). The results are shown in Table IV. 
The above experiment was repeated for additional times using 0.001 g, 0.001 
g, 0.01 g and 0.1 g of 10% w palladium on carbon catalyst (Baker and Co., 
Inc.) in addition to the base case concentration of solubilized catalyst. 
The results are shown in Table IV. Column 3 gives the average rate (R) of 
formation of 1,7-octadiene in the product per hour. Column 4 reports the 
percentage of the butadiene reactant originally present in the reaction 
which is converted to the desired 1,7-octadiene product in one hour 
reaction time. Column 5 is the rate (R) normalized to the rate obtained 
using solubilized palladium alone (R.sub.o), and column 6 gives the ratio 
of supported palladium to solubilized palladium. 
TABLE IV 
__________________________________________________________________________ 
Rate % w 
% of Butadiene 
1,7-Octadiene 
Reactant Converted 
Normalized 
Supported Pd/ 
Moles of Palladium Added 
In Product 
1,7-Octadiene 
Rate Solubilized 
Solubilized 
Supported 
Per Hour 
In 1 Hour R/R.sub.o 
Pd 
__________________________________________________________________________ 
9 .times. 10.sup.-6 
-- 1.70 10 1.0 -- 
9 .times. 10.sup.-6 
9.4 .times. 10.sup.-5 
0.70 4.1 0.4 10 
9 .times. 10.sup.-6 
9.4 .times. 10.sup.-6 
1.80 10.6 1.06 1 
9 .times. 10.sup.-6 
9.4 .times. 10.sup.-7 
3.3 19.4 1.94 0.1 
9 .times. 10.sup.-6 
9.4 .times. 10.sup.-8 
2.7 15.9 1.59 0.01 
__________________________________________________________________________ 
Illustrative Embodiment V 
To an 80 ml glass-lined autoclave were charged 2.7.times.10.sup.-5 moles of 
palladium acetate, 1.08.times.10.sup.-4 moles of (isopropyl) phosphine, 
2.5 g of triethylamine-formic acid salt, 10 ml of pyridine and 5 g of a 
BBB stream containing 40.34% 1,3-butadiene. The stirred reactor was heated 
to 40.degree. C. for 1 hour, cooled and the product was analyzed by gas 
chromatography for the amount of 1,7-octadiene present, giving a rate of 
0.12% w 1,7-octadiene per hour. The above reaction was repeated adding 
0.01 g of 10% Pd/C (Baker 100 mesh) and 2% hydrogen basis butadiene to the 
reaction mixture. The rate was increased to 3.98% w 1,7-octadiene per 
hour.