# US 5,703,254 A · Propylene oxide process using mixed precious metal catalyst supported on alkaline earth metal carbonate > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,703,254 A - Document ID: US5703254A - Status: Granted - Kind: A - Application number: 08/724,936 - Filed: 1996-10-02 - Granted: 1997-12-30 - Earliest claimed: 1996-10-02 - Assignees: Arco Chemical Technology, L.P. - Inventors: Anne M. Gaffney; Andrew P. Kahn; Rangasamy Pitchai - Web page: https://patentgrep.com/patent/US5703254A ## CPC - C07D 301/10: with catalysts containing silver or gold - Y02P 20/52: using catalysts, e.g. selective catalysts - C07D: HETEROCYCLIC COMPOUNDS (macromolecular compounds C08) - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS ## Abstract Propylene is oxidized to propylene oxide in the vapor phase using oxygen and a supported catalyst comprising silver, gold, a potassium promoter such as potassium nitrate or potassium carbonate and a support comprised in whole or in substantial part of an alkaline earth metal carbonate. ## Claims ### Claim 1 A process for producing propylene oxide wherein a feedstream comprising oxygen and propylene is contacted in the vapor phase at a temperature of 180.degree. C. to 350.degree. C. with a supported catalyst comprising (a) a support comprising an alkaline earth metal carbonate; (b) a catalytically effective amount of silver; (c) an amount of gold effective to improve selectivity to propylene oxide, wherein said gold is derived from a gold compound selected from the group consisting of gold hydroxide, gold carboxylates and mixtures thereof; and (d) a promoting amount of a potassium promoter derived from a potassium salt comprising potassium cation and an anion selected from carbon oxyanions, nitrogen oxyanions and precursors thereof. ### Claim 2 (depends on 1) The process of claim 1 wherein the alkaline earth metal carbonate is calcium carbonate. ### Claim 3 (depends on 1) The process of claim 1 wherein the potassium salt is selected from the group consisting of potassium carbonate, potassium bicarbonate, potassium nitrate, potassium nitrite and mixtures thereof. ### Claim 4 (depends on 1) The process of claim 1 wherein the supported silver catalyst is comprised of 5 to 50 weight percent silver based on the total weight of the supported silver catalyst. ### Claim 5 (depends on 1) The process of claim 1 wherein the potassium promoter is present in an amount of from 0.5 to 3 percent by weight, calculated as potassium cation, based on the total weight of the supported silver catalyst. ### Claim 6 (depends on 1) The process of claim 1 wherein the amount of gold present is from 1 to 10 weight percent based on the total weight of the supported silver catalyst. ### Claim 7 (depends on 1) The process of claim 1 wherein the feedstream is characterized by the absence of an organic halide. ### Claim 8 A process for producing propylene oxide wherein a feedstream comprising oxygen and propylene is contacted in the vapor phase at a temperature of 200.degree. C. to 300.degree. C. with a supported silver catalyst comprising (a) a support comprising calcium carbonate; (b) from 5 to 50 percent, based on the total weight of supported catalyst, of silver; (c) from 1 to 10 weight percent, based on the total weight of supported catalyst, of gold, wherein said gold is derived from a gold compound selected from the group consisting of gold hydroxide, gold carboxylates, and mixtures thereof; and (d) from 0.5 to 3 percent by weight, calculated as potassium cation based on the total weight of supported silver catalyst, of a potassium promoter derived from a potassium salt selected from the group consisting of potassium carbonate, potassium bicarbonate, potassium nitrate, potassium nitrite and mixtures thereof. ### Claim 9 (depends on 8) The process of claim 8 wherein the feedstream is characterized by the absence of an organic halide. ### Claim 10 (depends on 8) The process of claim 8 wherein the supported silver catalyst additionally comprises a promoting amount of a molybdenum promoter. ### Claim 11 A process for producing propylene oxide wherein a feedstream comprising oxygen and propylene and characterized by the absence of an organic halide is contacted in the vapor phase at a temperature of 180.degree. C. to 350.degree. C. with a supported catalyst comprising (a) a support comprising an alkaline earth metal carbonate; (b) a catalytically effective amount of silver; (c) an amount of gold effective to improve selectivity to propylene oxide; and (d) a promoting amount of potassium promoter derived from a potassium salt comprising potassium cation and an anion selected from carbon oxyanions, nitrogen oxyanions and precursors thereof. ### Claim 12 (depends on 11) The process of claim 11 wherein the alkaline earth metal carbonate is calcium carbonate. ### Claim 13 (depends on 11) The process of claim 11 wherein the potassium salt is selected from the group consisting of potassium carbonate, potassium bicarbonate, potassium nitrate, potassium nitrite and mixtures thereof. ### Claim 14 (depends on 11) The process of claim 11 wherein the supported silver catalyst is comprised of 5 to 50 weight percent silver based on the total weight of the supported silver catalyst. ### Claim 15 (depends on 11) The process of claim 11 wherein the potassium promoter is present in an amount of from 0.5 to 3 percent by weight, calculated as potassium cation, based on the total weight of the supported silver catalyst. ### Claim 16 (depends on 11) The process of claim 11 wherein the gold is derived from a gold compound selected from the group consisting of gold hydroxide, gold carboxylates and mixtures thereof. ### Claim 17 (depends on 11) The process of claim 11 wherein the amount of gold present is from 1 to 10 weight percent based on the total weight of the supported silver catalyst. ### Claim 18 A process for producing propylene oxide wherein a feedstream comprising oxygen and propylene and characterized by the absence of an organic halide is contacted in the vapor phase at a temperature of 200.degree. C. to 300.degree. C. with a supported silver catalyst comprising (a) a support comprising calcium carbonate; (b) from 5 to 50 percent, based on the total weight of supported catalyst, of silver; (c) from 1 to 10 weight percent, based on the total weight of supported catalyst, of gold; and (d) from 0.5 to 3 percent by weight, calculated as potassium cation based on the total weight of supported silver catalyst, of a potassium promoter derived from a potassium salt selected from the group consisting of potassium carbonate, potassium bicarbonate, potassium nitrate, potassium nitrite and mixtures thereof. ### Claim 19 (depends on 18) The process of claim 18 wherein the gold is derived from a gold compound selected from the group consisting of gold hydroxide, gold carboxylates, and mixtures thereof. ### Claim 20 (depends on 18) The process of claim 18, wherein the supported silver catalyst additionally comprises a promoting amount of a molybdenum promoter.