Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
158 words
A catalyst in the form of spherules or extrudates, comprising palladium and silver, incorporated as metallic particles on an alumina support, at least 30% of said metallic particles containing both palladium and silver, as measured by electron microscopy said alumina support having a specific surface of from 5 to 60 m 2 /g, the weight ratio of silver to palladium being higher than 0.4:1 to 3:1, a proportion of at least 80% of the palladium and a proportion of at least 80% of silver being present in a volume at the periphery of the catalyst delimited by a spherical or cylindrical surface with radius r 1 corresponding to the average radius of the catalyst spheniles or extrudates and a spherical or cylindrical surface with radius r 2 corresponding to the average radius of the catalyst spherules or extrudates and a spherical or cylindrical surface with radius r 2 which is at least equal to 0.8 r 1 .
Claim 2
Dependent Claim
158 words
A catalyst in the form of spherules or extrudates, comprising palladium and silver, incorporated as metallic particles on an alumina support, at least 30% of said metallic particles containing both palladium and silver, as measured by electron microscopy said alumina support having a specific surface of from 5 to 60 m 2 /g, the weight ratio of silver to palladium being higher than 0.4:1 to 3:1, a proportion of at least 80% of the palladium and a proportion of at least 80% of silver being present in a volume at the periphery of the catalyst delimited by a spherical or cylindrical surface with radius r 1 corresponding to the average radius of the catalyst spheniles or extrudates and a spherical or cylindrical surface with radius r 2 corresponding to the average radius of the catalyst spherules or extrudates and a spherical or cylindrical surface with radius r 2 which is at least equal to 0.8 r 1 .
Claim 3
Dependent Claim
19 words
A catalyst according to claim 1, wherein at least 50% of the metallic particles contain both palladium and silver.
Claim 4
Dependent Claim
18 words
A catalyst according to claim 2, wherein the weight ratio of silver to palladium is 0.5:1 to 3:1.
Claim 5
Dependent Claim
40 words
A catalyst according to claim 1 wherein: the palladium content is 0.01% to 0.5% by weight; the silver content is 0.001% to 0.1% by weight; and the alumina has a specific surface area of 5 to 15 m 2 /g.
Claim 6
Dependent Claim
15 words
A catalyst according to claim 1 further comprising at least one alkali or alkaline-earth metal.
Claim 7
Dependent Claim
21 words
A catalyst according to claim 5, wherein the atomic ratio of alkali or alkaline-earth metal to palladium is 2:1 to 20:1.
Claim 8
Dependent Claim
19 words
A catalyst according to claim 6, wherein the alkali or alkaline-earth metal content is 0.05% to 0.2% by weight.
Claim 9
Dependent Claim
27 words
The catalyst of claim 1, wherein said catalyst consists essentially of said alumina support and said palladium, silver, and at least one alkali or alkaline earth metal.
Claim 10
Dependent Claim
18 words
A catalyst according to claim 1, wherein the weight ratio of silver to palladium is 0.5:1 to 3:1.
Claim 11
Dependent Claim
18 words
A catalyst according to claim 5, wherein the weight ratio of silver to palladium is 0.5:1 to 3:1.
Claim 12
Dependent Claim
18 words
A catalyst according to claim 1, wherein the weight ratio of silver to palladium is 0.5:1 to 2.5:1.
Claim 13
Dependent Claim
21 words
A catalyst in accordance with claim 1, wherein the specific surface is 5 m 2 /g to 15 m 2 /g.
Claim 14
Dependent Claim
96 words
In a process for selective gas phase hydrogenation of at least one acetylenic hydrocarbon containing 2 or 3 carbon atoms to the corresponding ethylenic hydrocarbon, comprising passing an ethylene feed comprising at least one acetylenic hydrocarbon containing 2 or 3 carbon atoms in the gas phase in the presence of hydrogen over a hydrogenation catalyst in the form of spherules or extrudates, under hydrogenating conditions and wherein the catalyst is deactivated as the hydrogenation proceeds, the improvement comprising decreasing the rate of deactivation by employing a catalyst in accordance with claim 1 as said hydrogenation catalyst.
Claim 15
Dependent Claim
18 words
A process according to claim 13, wherein the weight ratio of silver to palladium is 0.5:1 to 3:1.
Claim 16
Dependent Claim
24 words
The process of claim 12, wherein the molar ratio of said hydrogen to said acetylenic hydrocarbon is in the range of 1:1 to 2:1.
Claim 17
Dependent Claim
19 words
A process according to claim 13, wherein at least 50% of the metallic particles contain both palladium and silver.
Claim 18
Dependent Claim
42 words
A process according to claim 13, wherein: said alumina has a specific surface area of 5 to 60 m 2 /g; the palladium content is 0.01% to 0.5% by weight; and the group IB metal content is 0.001% to 0.1% by weight.
Claim 19
Dependent Claim
21 words
A process according to claim 17, wherein the alumina has a specific surface area of 5 to 15 m 2 /g.
Claim 20
Dependent Claim
20 words
A process according to claim 16, characterized in that the catalyst also contains at least one alkali or alkaline-earth metal.
Claim 21
Dependent Claim
21 words
A process according to claim 19, wherein the atomic ratio of alkali or alkaline-earth metal to palladium is 2:1 to 20:1.
Claim 22
Dependent Claim
19 words
A process according to claim 19, wherein the alkali or alkaline-earth metal content is 0.05% to 0.2% by weight.
Claim 23
Dependent Claim
24 words
A process according to claim 13, wherein the alumina in the catalyst has a specific surface area of 5 to 15 m 2 /g.
Claim 24
Dependent Claim
17 words
A process according to claim 22, said catalyst further comprising at least one alkali or alkaline-earth metal.
Claim 25
Dependent Claim
24 words
A process according to claim 23, wherein the atomic ratio of alkali or alkaline-earth metal to palladium in the catalyst is 2:1 to 20:1.
Claim 26
Dependent Claim
22 words
A process according to claim 23, wherein the alkali or alkaline-earth metal content is in the catalyst 0.05% to 0.2% by weight.
Claim 27
Dependent Claim
24 words
A process in accordance with claim 19, wherein the specific surface of the alumina support is 5 m 2 /g to 15 2 /g.
Claim 28
Dependent Claim
87 words
In a process for selective gas phase hydrogenation of acetylene to the corresponding ethylenic hydrocarbon, comprising passing an ethylene feed, consisting essentially of ethylene and a minor quantity of acetylene as a contaminant, in the gas phase in the presence of hydrogen over a hydrogenation catalyst in the form of spherules or extrudates, under hydrogenating conditions and wherein the catalyst is deactivated as the hydrogenation proceeds, the improvement comprising decreasing the rate of deactivation by employing a catalyst in accordance with claim 1 as said hydrogenation catalyst.