Claims
- 1. A catalytic composite comprising a porous carrier material containing, on an elemental basis, about 0.01 to about 2 wt. % platinum or palladium, about 0.01 to about 2 wt. % rhodium, about 0.1 to about 5 wt. % tin, and about 0.01 to about 5 wt. % alkali metal or alkaline earth metal, wherein the platinum or palladium, rhodium, tin, and alkali metal or alkaline earth metal are uniformly dispersed throughout the porous carrier material, wherein substantially all of the platinum or palladium and rhodium are present in the elemental metallic state, wherein substantially all of the tin and alkali metal or alkaline earth metal are present in an oxidation state above that of the elemental metal and wherein substantially all of the tin is present in a particle size which is less than 100 Angstroms in maximum dimension.
- 2. A catalytic composite as defined in claim 1 wherein the porous carrier material is a refractory inorganic oxide.
- 3. A catalytic composite as defined in claim 2 wherein the refractory inorganic oxide is alumina.
- 4. A catalytic composite as defined in claim 1 wherein the alkali metal or alkaline earth metal is potassium.
- 5. A catalytic composite as defined in claim 1 wherein the alkali metal or alkaline earth metal is lithium.
- 6. A catalytic composite as defined in claim 1 wherein substantially all of the tin is present in the catalytic composite as tin oxide.
- 7. A catalytic composite as defined in claim 1 wherein the composite contains, on an elemental basis, about 0.05 to about 1 wt. % platinum or palladium, about 0.05 to about 1 wt. % rhodium, about 0.05 to about 1 wt. % tin, and about 0.25 to about 3.5 wt. % alkali metal or alkaline earth metal.
- 8. A catalytic composite as defined in claim 1 wherein the metals contents thereof is adjusted so that the atomic ratio of tin to platinum or palladium is about 0.1:1 to about 3:1, the atomic ratio of rhodium to platinum or palladium is about 0.1:1 to about 2:1, and the atomic ratio of alkali metal or alkaline earth metal is about 5:1 to about 50:1.
- 9. A catalytic composite as defined in claim 1 in sulfided form and containing about 0.01 to about 0.5 wt. % sulfur.
CROSS-REFERENCES TO RELATED APPLICATIONS
This application is a continuation-in-part of my prior, copending application Ser. No. 480,793 filed June 19, 1974, now U.S. Pat. No. 3,898,154; which in turn is a continuation-in-part of my prior application Ser. No. 376,841 filed July 5, 1973, and now U.S. Pat. No. 3,846,283; which in turn is a continuation-in-part of my prior application Ser. No. 201,576 filed Nov. 23, 1971, and now U.S. Pat. No. 3,745,112 and which in turn is a continuation-in-part of my prior application Ser. No. 807,910 filed Mar. 17, 1969, and now U.S. Pat. No. 3,740,328. All of the teachings of these prior applications are specifically incorporated herein by reference.
US Referenced Citations (4)
Continuation in Parts (4)
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Number |
Date |
Country |
Parent |
480793 |
Jun 1974 |
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Parent |
376841 |
Jul 1973 |
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Parent |
201576 |
Nov 1971 |
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Parent |
807910 |
Mar 1969 |
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