Hydrocarbon synthesis from CO and H.sub.2 using Ru supported on group VB metal oxides

An improved method for the synthesis of hydrocarbons with reduced methane formation and for the selective generation of olefinic hydrocarbons, preferably C.sub.2 -C.sub.5 olefins inclusive, which method comprises the steps of passing a CO and H.sub.2 synthesis gas stream over a catalyst at a temperature and pressure for a time sufficient to generate the desired olefinic products, wherein the improvement consists in using as a catalyst ruthenium on a support comprising at least one refractory Group VB metal oxide. The weight loading of the ruthenium may range from about 0.01 to about 15 wt. % based on the total catalyst weight. The ruthenium average crystallite size is preferably less than 5 nm (50A). The operating conditions of the instant process are typical for Fischer-Tropsch synthesis.

FIELD OF THE INVENTION 
Brief Description of the Invention 
An improved method for the synthesis of hydrocarbons with reduced methane 
formation and for the selective generation of olefinic hydrocarbons, 
preferably C.sub.2 -C.sub.5 olefins inclusive, which method comprises the 
steps of passing a CO and H.sub.2 synthesis gas stream over a catalyst at 
a temperature and pressure for a time sufficient to generate the desired 
olefinic products wherein the improvement consists in using as a catalyst 
ruthenium on a support comprising at least one refractory Group VB metal 
oxide. The weight loading of the ruthenium may range from about 0.01 to 
about 15 wt.% based on the weight of the total catalyst. The ruthenium 
average crystallite size is preferably less than 5 nm (50 A). The 
operating conditions of the instant process are typical for 
Fischer-Tropsch synthesis. 
DETAILED DESCRIPTION OF THE INVENTION 
An improved method for the synthesis of hydrocarbons with reduced methane 
formation and for the selective generation of olefinic hydrocarbons, 
preferably C.sub.2 -C.sub.5 olefins inclusive, which method comprises the 
steps of passing a CO and H.sub.2 synthesis gas stream over a catalyst at 
a temperature and pressure for a time sufficient to generate the desired 
olefinic products wherein the improvement consists in using as a catalyst 
ruthenium on a support comprising at least one refractory Group VB metal 
oxide. 
The instant invention presents an improvement in the Fischer-Tropsch 
hydrocarbon synthesis method in that it has been discovered unexpectedly 
that a ruthenium catalyst supported on a refractory Group VB metal oxide, 
or mixtures thereof, when utilized in conjunction with the Fischer-Tropsch 
method, will generate, with greater selectivity, olefinic hydrocarbons 
with reduced production of methane and other paraffinic products. 
The instant process exhibits this selectivity to olefinic products, 
preferably C.sub.2 -C.sub.5 olefins inclusive, when the catalyst utilized 
comprises ruthenium supported on a supported selected from the group 
consisting of a refractory Group VB metal oxide, or mixtures thereof, 
preferably V.sub.2 O.sub.3, Nb.sub.2 O.sub.5 and Ta.sub.2 O.sub.5. The 
support may also be selected from the group consisting of V.sub.2 O.sub.3, 
Nb.sub.2 O.sub.5, Ta.sub.2 O.sub.5, Al.sub.2 O.sub.3 -V.sub.2 O.sub.3, 
Al.sub.2 O.sub.3 -Nb.sub.2 O.sub.5, Al.sub.2 O.sub.3 -Ta.sub.2 O.sub.5, 
SiO.sub.2 -V.sub.2 O.sub.3, SiO.sub.2 -Ta.sub.2 O.sub.5, SiO.sub.2 
-Nb.sub.2 O.sub.5, V.sub.2 O.sub.3 -carbon, Nb.sub.2 O.sub.5 -carbon, 
Ta.sub.2 O.sub.5 -carbon, alkaline earth-Group VB oxides, alkali-Group VB 
oxides, rare earth Group VB oxides, Group IVB-Group VB oxides, or mixtures 
thereof, but is preferably oxides of vanadium, oxides of tantalum and 
oxides of niobium or mixtures thereof or admixed with alumina, silica or 
Group IVB oxides. Most preferably, the support comprises essentially pure 
V.sub.2 O.sub.3, Nb.sub.2 O.sub.5 or Ta.sub.2 O.sub.5 or mixtures thereof 
either alone or in combination with alumina, silica or Group IVB oxides. 
It is also possible to admix with these materials other refractory 
materials that will not substantially inhibit the Fischer-Tropsch 
hydrocarbon synthesis characteristics of ruthenium supported on at least 
one Group VB metal oxide as herein described. The supports which may be 
used in the practice of this invention may be in any form, such as 
powders, pellets, spheres, extrudates, etc. and may have a B.E.T. surface 
area of from about 1 to about 200 m.sup.2 g.sup.-1, preferably from about 
10 to about 100 m.sup.2 g.sup.-1, most preferably from 25 to about 100 
m.sup.2 g.sup.-1. With most metal catalysts, the higher the surface area 
of the support, the higher the dispersion of the supported metal at a 
given weight loading. It is therefore desirable to use a support with as 
high a surface area as possible to maximize the dispersion of the 
ruthenium metal. Ruthenium is deposited on the chosen support in a 
concentration of from about 0.01 to about 15 wt.%, preferably from about 
0.1 to about 10 wt.%, and most preferably from about 0.5 to about 5 wt.%, 
the percentages based on total weight of catalyst with the ruthenium 
possessing an average crystallite size, as determined by standard 
techniques such as X-ray diffraction of from about 1 to about 20 nm, 
preferably about 1 to about 10 nm, and most preferably from about 1 to 
about 5 nm. Using standard experimental techniques, for a ruthenium on 
Nb.sub.2 O.sub.5 (650), Ta.sub.2 O.sub.5 (650) or V.sub.2 O.sub.3 (650) 
system, reduced in hydrogen at 450.degree. C., X-ray diffraction shows no 
particles of Ru in the reduced catalyst, indicating particles of Ru having 
crystallite sizes of less than 5 nm, which corresponds to a dispersion of 
greater than 20%. 
Ruthenium catalysts comprising ruthenium supported on a support comprising 
a refractory Group VB metal oxide, or mixtures thereof, exhibit greater 
selectivity to the production of olefinic products with decreased methane 
formation as compared with typical ruthenium catalysts of the prior art. 
The prior art catalysts are either unsupported or supported on such 
materials as Al.sub.2 O.sub.3, SiO.sub.2 or carbon. 
The operating conditions of the instant process are typical for 
Fischer-Tropsch synthesis. The pressure may range from about 100 to about 
10.sup.5 kPa, preferably from about 100 to about 3100 kPa, and most 
preferably from about 100 to about 2060 kPa. The temperature may range 
from about 100.degree. to about 500.degree. C., preferably from about 
150.degree. to about 400.degree. C., and most preferably from about 
150.degree. to about 300.degree. C. The H.sub.2 /CO ratio may range from 
about 0.1 to about 10, preferably from about 0.5 to about 4, most 
preferably from about 1 to about 3. The space velocity may range from 
about 100 hr.sup.-1 to about 50,000 hr.sup.-1. 
The ruthenium catalysts employed in the practice of the instant process are 
themselves prepared by techniques known in the art for the preparation of 
other catalyst systems, such as Ru on Al.sub.2 O.sub.3, etc. A suitable 
ruthenium salt, such as ruthenium chloride, ruthenium nitrate or ruthenium 
acetate, etc., is dissolved in a solvent such as water or any other 
suitable solvent and stirred with the chosen Group VB metal oxide support 
system. After thorough mixing the mixture is allowed to dry and then heat 
treated in air at a temperature of from 100.degree. to 150.degree. C. or 
alternatively may be dried immediately by heating in air at a temperature 
of between 100.degree. and 150.degree. C. for several hours. 
In a preferred embodiment, the ruthenium catalyst, prepared as outlined 
above, or by similar techniques, is heat treated in a reducing atmosphere 
such as hydrogen at a temperature greater than 300.degree. C., preferably 
greater than 400.degree. C., most preferably greater than 500.degree. C., 
for from typically 0.5 to 4 hours, preferably from 1-2 hours. U.S. Ser. 
No. 771,396, filed Feb. 23, 1977, copending application of S. J. Tauster, 
L. L. Murrell and S. C. Fung, teaches the procedures of preparing 
catalysts by this method and is hereby incorporated by reference. It 
should be noted that this heat treating reduction step need not be 
practiced as a separate step, since the Fischer-Tropsch synthesis is 
practiced in a reducing atmosphere and will, therefore, have a similar 
reduction effect on the catalyst as the above step. The supported 
ruthenium catalyst system utilized in the instant process may have an 
average ruthenium crystallite size of preferably less than 5 nm.

The following examples are presented to illustrate and not limit the 
instant invention. 
EXAMPLE 1 
The selectivity in a Fischer-Tropsch synthesis for ruthenium catalysts 
supported by Nb.sub.2 O.sub.5 is compared to ruthenium catalysts both 
unsupported and supported by support materials of the prior art. 
A 1% Ru/Nb.sub.2 O.sub.5 catalyst was prepared in the following manner. 
Nb.sub.2 O.sub.5 was prepared by the addition of a methanolic solution of 
NbCl.sub.5 to a methanolic solution of NH.sub.4 OH, producing a gel. The 
latter was washed with H.sub.2 O, then with 0.2 M NH.sub.4 NO.sub.3, 
followed by another wash with H.sub.2 O. This gel was dried at 110.degree. 
C. The dried gel was calcined in air at 600.degree. C. for 16 hours. X-ray 
inspection of the calcined product indicated the presence of Nb.sub.2 
O.sub.5 with no other phases apparent. The surface area (B.E.T.) was 7.9 
m.sup.2 /g. A portion of Nb.sub.2 O.sub.5 was treated in flowing H.sub.2 
(20% in He) at 650.degree. for 11/2 hours. The product was labeled 
Nb.sub.2 O.sub.5 (650). X-ray inspection showed the presence of Nb.sub.2 
O.sub.5 and of NbO.sub.2, the latter being in a lesser amount. 
The Nb.sub.2 O.sub.5 and Nb.sub.2 O.sub.5 (650) prepared in the above 
manner were impregnated by the method of incipient wetness with aqueous 
solutions of RuCl.sub.3. The impregnates were dried at 110.degree. C. The 
amount of RuCl.sub.3 used was calculated to provide 1% Ru by total weight 
of catalyst after reduction in H.sub.2. The RuCl.sub.3 /Nb.sub.2 O.sub.5 
was charged after drying into the catalytic reactor for in situ reduction 
in H.sub.2. 
The RuCl.sub.3 /Nb.sub.2 O.sub.5 (650) was treated in flowing H.sub.2 (20% 
in He) at 650.degree. C., for 11/2 hours, then cooled in flowing He and 
passivated by treatment with flowing, dilute O.sub.2 (1% in He) at 
25.degree. C. This material was thereupon charged into the catalytic 
reactor where it underwent in situ reduction in H.sub.2. 
The ruthenium metal catalyst was prepared as follows. NH.sub.4 OH was added 
to an aqueous solution of RuCl.sub.3 precipitating Ru(OH).sub.3 which was 
subsequently dried at 110.degree.-120.degree. C. in air. It was then 
charged to the reactor and flushed with He at room temperature. The 
H.sub.2 concentration in the He stream was slowly increased at a rate such 
that the sample did not heat up excessively. When 100% H.sub.2 was flowing 
over the sample, the temperature was increased to 300.degree. C. over a 
period of 1 hour and held at 300.degree. C. for 1 hour. Subsequently it 
was cooled to reaction temperature in H.sub.2 for catalytic studies. The 
ruthenium catalysts supported on carbon, SiO.sub.2 and .eta.-Al.sub.2 
O.sub.3 were made in a manner similar to the Ru/Nb.sub.2 O.sub.5 : the 
ruthenium was deposited on the supports by the incipient wetness technique 
using RuCl.sub.3 ; they were dried at 110.degree.-120.degree. C. in air; 
and reduced in situ. The carbon for the ruthenium on carbon catalyst was 
Carbolac-1, obtained from the Cabot Corporation, had a B.E.T. surface area 
of 950 m.sup.2 g.sup.-1. The SiO.sub.2 for the ruthenium on SiO.sub.2 
catalyst was Cab-O-Sil (HS-5), obtained from the Cabot Corporation, had a 
B.E.T. surface area of 300 m.sup.2 g.sup.-1. The Al.sub.2 O.sub.3 for the 
ruthenium on .eta.-Al.sub.2 O.sub.3 was prepared by calcining alumina 
B-trihydrate (Al.sub.2 O.sub.3.3H.sub.2 O), obtained from Davison Chemical 
Co., at 600.degree. C. in air for 4 hours. It had a B.E.T. surface area of 
245 m.sup.2 g.sup.-1. 
TABLE I 
__________________________________________________________________________ 
SELECTIVITY OF VARIOUS RUTHENIUM CATALYSTS 
(Reaction Conditions: H.sub.2 /CO = 3; Pressure = 103 kPa) 
Hydrocarbon Product Distribution (Mole %) 
% CO C.sub.3 H.sub.6 
C.sub.4 H.sub.8 
C.sub.5 H.sub.10 
C.sub.2 -C.sub.5 
Catalyst T.degree.C. 
Conv 
CH.sub.4 
C.sub.2 H.sub.4 
C.sub.2 H.sub.6 
C.sub.3 H.sub.8 
C.sub.4 H.sub.10 
C.sub.5 H.sub.12 
C.sub.6.sup.+ 
Olefins 
C.sub.2.sup.+ 
__________________________________________________________________________ 
Ru metal.sup.c 
226 
3.5 96 0 4 TR. 
0 0 0 0 4 
4% Ru/Carbon.sup.b 
243 
2.5 98 0 2 TR. 
0 0 0 0 2 
234 
1.6 98 0 2 0 0 0 0 0 2 
1% Ru/SiO.sub.2.sup.a 
232 
4.1 87 1/2 
7 4 1 1 TR. 
21/2 
13 
5% Ru/SiO.sub.2.sup.a 
233 
16.7 
86 TR. 
8 4 11/2 
1 TR. 
TR. 14 
1% Ru/Al.sub.2 O.sub.3.sup.a 
228 
8.8 66 
12---- 81/2 
6 41/2 
3 11 34 
244 
14.1 
71 
11---- 7 5 4 2 10 29 
Ru/Al.sub.2 O.sub.3.sup.a 
239 
13.6 
67 1/2 
10 10 10 6 5 -- 33 
1% Ru/Nb.sub.2 O.sub.5.sup.a 
234 
7.8 48 
11---- 13 10 7 12 22 52 
1% Ru/Nb.sub.2 O.sub.5 (650).sup.a 
244 
5.7 41 
14---- 18 11 11 5 27 59 
__________________________________________________________________________ 
.sup.a Catalysts reduced for 1 hour at 450.degree. C. before feed 
introduced. 
.sup.b Catalyst reduced for 1 hour at 400.degree. C. before feed 
introduced. 
.sup.c Catalyst reduced for 1 hour at 300.degree. C. before feed 
introduced. 
Table I illustrates in a Fischer-Tropsch synthesis the desirable 
selectivity characteristics of Ru/Nb.sub.2 O.sub.5 catalysts as compared 
with unsupported Ru metal or with catalysts consisting of ruthenium 
supported on other support materials. In particular, it should be noted 
that the formation of methane is significantly lower for the Ru/Nb.sub.2 
O.sub.5 catalysts than for the other catalysts listed. Thus, whereas the 
selectivity in the production of C.sub.2 + is up to 34 mole % for all the 
other catalysts listed in Table I, values up to 59 moles % are obtained 
for a Ru catalyst supported on Nb.sub.2 O.sub.5. A further desirable 
feature of the Ru/Nb.sub.2 O.sub.5 catalyst is its enhanced formation of 
C.sub.2 -C.sub.5 olefins. These olefins are useful chemical intermediates 
for the production of plastics, rubber, alcohols, ketones, aldehydes, 
esters and acids. It is shown in Table I that the Ru/Nb.sub.2 O.sub.5 
catalysts exhibit at least twice the selectivity in the production of 
C.sub.2 -C.sub.5 olefins as any other catalyst listed. 
EXAMPLE 2 
The selectivity in a Fischer-Tropsch synthesis for ruthenium catalysts 
supported by Ta.sub.2 O.sub.5 is compared to ruthenium catalysts both 
unsupported and supported by support materials of the prior art. 
A 1% Ru/Ta.sub.2 O.sub.5 catalyst was prepared in the following manner. 
Ta.sub.2 O.sub.5 was prepared by the addition of a methanolic solution of 
TaCl.sub.5 to a methanolic solution of NH.sub.4 OH, producing a gel. The 
latter was washed with H.sub.2 O, then with 0.2 M NH.sub.4 NO.sub.3, 
followed by another wash with H.sub.2 O. This gel was dried at 110.degree. 
C. The dried gel was calcined in air at 600.degree. C. for 4 hours. X-ray 
inspection of the calcined product indicated the presence of Ta.sub.2 
O.sub.5 with no other phases apparent. The material was recalcined in air 
at 700.degree. C. for 16 hours. The surface area (B.E.T.) was 5.3 m.sup.2 
/g. 
A portion of the Ta.sub.2 O.sub.5 was treated with flowing H.sub.2 (20% in 
He) at 650.degree. C. for 11/2 hours. The product was labeled Ta.sub.2 
O.sub.5 (650). X-ray inspection again showed Ta.sub.2 O.sub.5 with no 
other phases apparent. 
Ta.sub.2 O.sub.5 and Ta.sub.2 O.sub.5 (650) were impregnated by the method 
of incipient wetness with aqueous solutions of RuCl.sub.3. The amount of 
RuCl.sub.3 was calculated to provide 1% Ru by weight after reduction in 
H.sub.2. RuCl.sub.3 /Ta.sub.2 O.sub.5 was charged, after drying, into the 
catalytic reactor for in situ reduction in H.sub.2. 
RuCl.sub.3 /Ta.sub.2 O.sub.5 (650) was treated in flowing H.sub.2 (20% in 
He) at 650.degree. C., for 11/2 hours, then cooled in flowing He and 
passivated by treatment with flowing, dilute O.sub.2 (1% in He) 25.degree. 
C. This material was thereupon charged into the catalytic reactor wherein 
it underwent in situ activation in H.sub.2. The other catalysts were 
prepared as described in Example 1. 
Table II illustrates in a Fischer-Tropsch synthesis the desirable 
selectivity characteristics of Ru/Ta.sub.2 O.sub.5 catalysts as compared 
with unsupported Ru metal or with catalysts consisting of ruthenium 
supported on other support materials. The other catalysts were prepared as 
described in Example 1. The data pertaining to Ru metal, Ru/carbon, 
Ru/SiO.sub.2 and Ru/Al.sub.2 O.sub.3 are identical to that presented in 
Table I and are repeated for convenience. It is seen that the desirable 
selectivity characteristics which were pointed out with respect to 
Ru/Nb.sub.2 O.sub.5 catalysts in Table I also apply to Ru/Ta.sub.2 O.sub.5 
catalysts. Thus, the molar selectivities of the Ru/Ta.sub.2 O.sub.5 
catalyst in the production of C.sub.2 + hydrocarbons are in excess of 
50%--considerably greater than the molar selectivity to the C.sub.2 + 
hydrocarbons of the prior art catalysts listed. Table II also indicates 
that the Ru/Ta.sub.2 O.sub.5 catalysts exhibit markedly enhanced 
selectivity in the production of C.sub.2 -C.sub.5 olefins as compared to 
any other catalyst listed. 
TABLE II 
__________________________________________________________________________ 
SELECTIVITY OF VARIOUS RUTHENIUM CATALYSTS 
(Reaction Conditions: H.sub.2 /CO = 3; Pressure = 103 kPa) 
Hydrocarbon Product Distribution (Mole %) 
T % CO C.sub.3 H.sub.6 
C.sub.4 H.sub.8 
C.sub.5 H.sub.10 
C.sub.2 --C.sub.5 
Catalyst .degree.C. 
Conv 
CH.sub.4 
C.sub.2 H.sub.4 
C.sub.2 H.sub.6 
C.sub.3 H.sub.8 
C.sub.4 H.sub.10 
C.sub.5 H.sub.12 
C.sub.6.sup.+ 
Olefins 
C.sub.2.sup.+ 
__________________________________________________________________________ 
Ru metal.sup.c 
226 
3.5 96 0 4 TR. 
0 0 0 0 4 
4% Ru/Carbon.sup.b 
243 
2.5 98 0 2 TR. 
0 0 0 0 2 
234 
1.6 98 0 2 0 0 0 0 0 2 
1% Ru/SiO.sub.2.sup.a 
232 
4.1 87 1/2 
7 4 1 1 TR. 
21/2 
13 
5% Ru/SiO.sub.2.sup.a 
233 
16.7 
86 TR. 
8 4 11/2 
1 TR. 
TR. 14 
1% Ru/Al.sub.2 O.sub.3.sup.a 
228 
8.8 66 
12---- 81/2 
6 41/2 
3 11 34 
244 
14.1 
71 
11---- 7 5 4 2 10 29 
5% Ru/Al.sub.2 O.sub.3.sup.a 
239 
13.6 
67 1/2 
10 10 10 6 5 -- 33 
1% Ru/Ta.sub.2 O.sub.5.sup.a 
228 
17.7 
46 
10---- 13 10 11 9 17 54 
1% Ru/Ta.sub.2 O.sub.5 (650).sup.a 
226 
10.3 
42 
10---- 16 12 9 11 27 58 
__________________________________________________________________________ 
.sup.a Catalysts reduced for 1 hour at 450.degree. C. before feed 
introduced. 
.sup.b Catalyst reduced for 1 hour at 400.degree. C. before feed 
introduced. 
.sup.c Catalyst reduced for 1 hour at 300.degree. C. before feed 
introduced. 
EXAMPLE 3 
The selectivity in a Fischer-Tropsch synthesis for ruthenium catalysts 
supported by V.sub.2 O.sub.3 is compared to ruthenium catalysts both 
unsupported and supported by other support materials of the prior art. 
A 1% Ru/V.sub.2 O.sub.3 catalyst was prepared in the following manner: 
V.sub.2 O.sub.3 was made as follows: NH.sub.4 VO.sub.3 was calcined at 
about 400.degree. C. in flowing air to give V.sub.2 O.sub.5. The surface 
area (B.E.T.) was 11 m.sup.2 /g. The V.sub.2 O.sub.5 was reduced in 
flowing H.sub.2 (20% in He) at 550.degree. C. for 21/2 hours. X-ray 
inspection showed V.sub.2 O.sub.3 with a small extraneous signal at 
20.degree.=27.degree.. The latter indicates the presence to a very small 
extent, of a crystallographic shear phase of the family, V.sub.m 
O.sub.2m-1. The surface area (B.E.T.) was 2.4 m.sup.2 /g. 
A portion of V.sub.2 O.sub.3 was treated in flowing H.sub.2 (20% in He) at 
650.degree. C. for 11/2 hours. The product was labelled V.sub.2 O.sub.3 
(650). X-ray inspection indicated the presence of V.sub.2 O.sub.3 with no 
other phases apparent. Thus, the very small amount of higher vanadium 
oxide present before H.sub.2 treatment at 650.degree. C. had been removed 
by this treatment. 
V.sub.2 O.sub.3 and V.sub.2 O.sub.3 (650) were impregnated by the method of 
incipient wetness with aqueous solutions of RuCl.sub.3. The impregnates 
were dried at 110.degree. C. The amount of RuCl.sub.3 used was calculated 
to provide 1% Ru by weight after reduction in H.sub.2. RuCl.sub.3 /V.sub.2 
O.sub.3 was charged, after drying, into the catalytic reactor for in situ 
reduction in H.sub.2. 
RuCl.sub.3 /V.sub.2 O.sub.3 (650) was treated in flowing H.sub.2 (20% in 
He) at 650.degree. C., 11/2 hours, then cooled in flowing He and 
passivated by treatment with flowing, dilute O.sub.2 (1% in He) at 
25.degree. C. This material was thereupon charged into the catalytic 
reactor where it underwent in situ activation in H.sub.2. 
Table III illustrates in a Fischer-Tropsch synthesis the desirable 
selectivity characteristics of Ru/V.sub.2 O.sub.3 catalysts as compared 
with unsupported Ru metal or with catalysts consisting of ruthenium 
supported on other support materials. The data pertaining to Ru metal, 
Ru/Carbon, Ru/SiO.sub.2 and Ru/Al.sub.2 O.sub.3 are identical to that 
presented in Tables I and II and are repeated in Table III for 
convenience. It is seen that the desirable selectivity characteristics 
which were demonstrated with respect to Ru/Nb.sub.2 O.sub.5 catalysts in 
Table I and Ru/Ta.sub.2 O.sub.5 catalysts in Table II also apply to 
Ru/V.sub.2 O.sub.3 catalysts. Thus, the molar selectivities of the 
Ru/V.sub.2 O.sub.3 catalysts in the production of C.sub.2 + are about 
50%--considerably greater than the molar selectivity to the C.sub.2 + 
hydrocarbons of the other catalysts listed. Formation of C.sub.2 -C.sub.5 
olefins is also markedly enhanced for Ru/V.sub.2 O.sub.3. In the case of 
Ru/V.sub.2 O.sub.3 (650), formation of propylene, butene and pentene was 
not measured. However, the high selectivity with which ethylene is formed 
by this catalyst (17% or 16%, as compared with 1/2% over 5% Ru/Al.sub.2 
O.sub.3) is significant. 
TABLE III 
__________________________________________________________________________ 
SELECTIVITY OF VARIOUS RUTHENIUM CATALYSTS 
(Reaction Conditions: H.sub.2 /CO = 3, Pressure = 103 kPa) 
Hydrocarbon Product Distribution (Mole %) 
T % CO C.sub.3 H.sub.6 
C.sub.4 H.sub.8 
C.sub.5 H.sub.10 
C.sub.2 -C.sub.5 
Catalyst .degree.C. 
Conv 
CH.sub.4 
C.sub.2 H.sub.4 
C.sub.2 H.sub.6 
C.sub.3 H.sub.8 
C.sub.4 H.sub.10 
C.sub.5 H.sub.12 
C.sub.6.sup.+ 
Olefins 
C.sub.2.sup.+ 
__________________________________________________________________________ 
Ru metal.sup.c 
226 
3.5 96 0 4 TR. 
0 0 0 0 4 
4% Ru/Carbon.sup.b 
243 
2.5 98 0 2 TR. 
0 0 0 0 2 
234 
1.6 98 0 2 0 0 0 0 0 2 
1% Ru/SiO.sub.2.sup.a 
232 
4.1 87 1/2 
7 4 1 1 TR. 
21/2 
13 
5% Ru/SiO.sub.2.sup.a 
233 
16.7 
86 TR. 
8 4 11/2 
1 TR. 
TR. 14 
1% Ru/Al.sub.2 O.sub.3.sup.a 
228 
8.8 66 
12---- 81/2 
6 41/2 
3 11 34 
244 
14.1 
71 
11---- 7 5 4 2 10 29 
5% Ru/Al.sub.2 O.sub.3.sup.a 
239 
13.6 
67 1/2 
10 10 10 6 5 -- 33 
1% Ru/V.sub.2 O.sub.3.sup.a 
243 
4.1 45 6 9 18 10 3 10 28 55 
1% Ru/V.sub.2 O.sub.3 (650).sup.a 
246 
0.7 55 17 4 17 6 -- -- -- 45 
259 
1.4 49 16 5 17 6 8 -- -- 51 
__________________________________________________________________________ 
.sup.a Catalysts reduced for 1 hour at 450.degree. C. before feed 
introduced 
.sup.b Catalyst reduced for 1 hour at 400.degree. C. before feed 
introduced 
.sup.c Catalyst reduced for 1 hour at 300.degree. C. before feed 
introduced