Method for preparation of catalytic material for selective oxidation and catalyst members thereof

Abstract

The invention pertains to the preparation and use of catalytic materials and catalyst members for the selective oxidation of carbon monoxide in a gas stream that contains hydrogen. One such catalyst member may be produced by depositing by electric arc spraying a metal feedstock onto a metal substrate to provide a metal anchor layer on the substrate, and depositing a catalytic material comprising platinum and iron dispersed on a refractory inorganic oxide support material onto the metal substrate. The catalytic material may optionally be produced by wetting the support material, especially a particulate support material, with a platinum group metal solution and iron solution and drying and calcining the wetted support material in air at a temperature in the range of from 200° C. to 300° C., preferably using a solution containing bivalent platinum ion species. The catalyst member may be used by flowing the gas stream therethrough at a temperature at about 90° C. with a O 2 :CO ratio of about 1:1 and a space velocity of about 20,000/hr or, alternatively, at a temperature of about 150° C. with a O 2 :CO ratio of about 1.5:1 and a space velocity of about 80,000/hr.

What is claimed is:  
     
         1 . A method of preparing a catalytic material, comprising wetting a refractory inorganic oxide support material with a bivalent platinum solution and iron solution and drying and calcining the wetted support material under oxidizing conditions at a temperature in the range of from 200° C. up to, but not including, 300° C.  
     
     
         2 . A method of preparing a catalytic material, comprising wetting a refractory inorganic oxide support material with a bivalent platinum solution and iron solution and drying and calcining the wetted support material under oxidizing conditions at a temperature in the range from 200° C. to 300° C. wherein the catalytic material is substantially free of at least one metal selected from the group consisting of palladium, rhodium and cerium.  
     
     
         3 . The method of  claim 1  wherein the support material is a powdered support material.  
     
     
         4 . The method of  claim 3  wherein the support material comprises powdered alumina.  
     
     
         5 . The method of  claim 1  wherein the support material comprises a pelletized support material.  
     
     
         6 . A method of preparing a catalyst member, comprising wetting a monolith comprising a refractory material with a bivalent platinum solution and iron solution and drying and calcining the wetted monolith under oxidizing conditions at a temperature in the range of from 200° C. up to but not including 300° C.  
     
     
         7 . A method of preparing a catalyst member, comprising wetting a monolith comprising a refractory material with a bivalent platinum solution and iron solution and drying and calcining the wetted monolith under oxidizing conditions at a temperature in the range of from 200° C. to 300° C., wherein the catalyst member is substantially free of at least one metal selected from the group consisting of palladium, rhodium and cerium.  
     
     
         8 . A catalytic material prepared by the method comprising wetting a refractory inorganic oxide support material with a bivalent platinum solution and an iron solution, and drying and calcining the wetted support material under oxidizing conditions at a temperature in the range of from 200° C. up to but not including 300° C.  
     
     
         9 . A catalytic material prepared by the method comprising wetting a refractory inorganic oxide support material with a bivalent platinum solution and an iron solution, and drying and calcining the wetted support material under oxidizing conditions at a temperature in the range of from 200° C. to 300° C. wherein the catalytic material is substantially free of at least one metal selected from the group consisting of palladium, platinum and cerium.  
     
     
         10 . The catalytic material of  claim 8  or  claim 9  wherein the support material comprises a powdered support material and wherein the catalytic species comprises platinum at a loading in the range of about 3 to 5 weight percent and iron at a loading of about 0.3 weight percent of the catalytic material.  
     
     
         11 . The catalytic material of  claim 8  or  claim 9  wherein the support material comprises alumina.  
     
     
         12 . The catalytic material of  claim 8  or  claim 9  wherein the support material comprises pelletized support material.  
     
     
         13 . A catalyst member prepared by the method comprising wetting a monolith comprising a refractory material with a bivalent platinum solution and an iron solution, and drying and calcining the wetted monolith under oxidizing conditions at a temperature in the range of from 200° C. up to but not including 300° C.  
     
     
         14 . A catalyst member prepared by the method comprising wetting a monolith comprising a refractory material with a bivalent platinum solution and an iron solution, and drying and calcining the wetted monolith under oxidizing conditions at a temperature in the range of from 200° C. to 300° C. wherein the catalyst member is substantially free of at least one metal selected from the group consisting of palladium, rhodium and cerium.  
     
     
         15 . A catalyst member comprising a carrier substrate having a catalytic material thereon, wherein the catalytic material is prepared by the method comprising wetting a refractory inorganic oxide support material with a bivalent platinum solution and an iron solution, and drying and calcining the wetted support material under oxidizing conditions at a temperature in the range of from 200° C. up to but not including 300° C.  
     
     
         16 . A catalyst member comprising a carrier substrate having a catalytic material thereon, wherein the catalytic material is prepared by the method comprising wetting a refractory inorganic oxide support material with a bivalent platinum solution and an iron solution, and drying and calcining the wetted support material under oxidizing conditions at a temperature in the range of from 200° C. to 300° C. wherein the catalyst member is substantially free of at least one metal selected from the group consisting of palladium, rhodium and cerium.  
     
     
         17 . The catalyst member of  claim 15  or  claim 16  wherein the support material comprises a powdered support material.  
     
     
         18 . The catalyst member of  claim 17  wherein the support material comprises alumina.  
     
     
         19 . The catalyst member of  claim 18  wherein the catalytic species comprises platinum at a loading in the range of from about 3 to 5 percent and iron at a loading of about 0.3 percent by weight of the catalytic material.  
     
     
         20 . The catalyst member of  claim 15  wherein the carrier substrate comprises a tube.  
     
     
         21 . The catalyst member of  claim 15  or  claim 16  comprising a coating of refractory inorganic oxide material on the carrier as a binder coat beneath the catalytic material.  
     
     
         22 . The catalyst member of  claim 15  or  claim 16  wherein the carrier substrate comprises a metal substrate having a surface layer of metal oxide.  
     
     
         23 . The catalyst member of  claim 22  wherein the metal substrate is calcined before the catalytic material is deposited thereon to produce the surface layer of metal oxide.  
     
     
         24 . The catalyst member of  claim 22  wherein the metal substrate comprises a foamed metal substrate.  
     
     
         25 . The catalyst member of  claim 23  wherein the metal substrate comprises a foamed metal substrate.  
     
     
         26 . A catalyst member comprising at least one tube mounted in a housing defining two fluid flow paths therethrough, the at least one tube having a catalytic material deposited thereon for exposure to at least one fluid flow path.  
     
     
         27 . The catalyst member of  claim 26  wherein the catalytic material is prepared by the method comprising wetting a refractory inorganic oxide support material with a platinum group metal solution and an iron solution, and drying and calcining the wetted support material under oxidizing conditions at a temperature in the range of from 200° C. up to but not including 300° C.  
     
     
         28 . The catalyst member of  claim 26  wherein the catalytic material is prepared by the method comprising wetting a refractory inorganic oxide support material with a platinum group metal solution and an iron solution, and drying and calcining the wetted support material under oxidizing conditions at a temperature in the range of from 200° C. to 300° C. wherein the catalytic material is substantially free of at least one metal selected from the group consisting of palladium, rhodium and cerium.  
     
     
         29 . The catalyst member of  claim 27  or  claim 28  wherein the solution comprises bivalent platinum ion species.  
     
     
         30 . The catalyst member of  claim 36 ,  claim 37  or  claim 38  comprising at least one tube having a metal anchor layer on which the catalytic material is deposited, the anchor layer being thermally sprayed onto the tubes.  
     
     
         31 . The catalyst member of  claim 30  wherein the anchor layer is electric arc sprayed onto at least one tube.  
     
     
         32 . The catalyst member of  claim 26  wherein the at least one tube has a coating of a refractory inorganic oxide material on the carrier as a binder coat beneath the catalytic material.  
     
     
         33 . The catalyst member of  claim 32  wherein the at least one tube comprises a metal tube having a surface layer of metal oxide.  
     
     
         34 . The catalyst member of  claim 33  wherein the metal tube is calcined before the catalytic material is deposited thereon to produce the surface layer of metal oxide.  
     
     
         35 . A method for oxidizing carbon monoxide in a gas stream containing carbon monoxide, hydrogen and oxygen, comprising contacting the gas stream at a temperature less than 300° C. with a catalytic material prepared by the method comprising wetting a refractory inorganic oxide support material with a platinum group metal solution and an iron solution, and drying and calcining the wetted support material under oxidizing conditions at a temperature in the range of from 200° C. to 300° C. to produce a catalytic material comprising catalytic species dispersed on the support material.  
     
     
         36 . A method for oxidizing carbon monoxide in a gas stream containing carbon monoxide, hydrogen and oxygen, comprising contacting the gas stream at a temperature less than 300° C. with a catalyst member prepared by the method comprising wetting a monolith with a platinum group metal solution and an iron solution, and drying and calcining the wetted monolith under oxidizing conditions at a temperature in the range of from 200° C. to 300° C.  
     
     
         37 . The method of  claim 35  or  claim 36  wherein the solution contains bivalent platinum ion species.  
     
     
         38 . The method of  claim 37  wherein the catalytic material comprises platinum at a loading of from about 3 to 5 percent by weight of platinum plus support material and iron at a loading of about 0.3 percent by weight of iron plus support material.  
     
     
         39 . The method of  claim 38  wherein the support material comprises alumina.  
     
     
         40 . The method of  claim 37  comprising contacting the gas stream at a temperature at about 90° C. with a O 2 :CO ratio of about 1:1 and a space velocity of about 20,000/hr.  
     
     
         41 . The method of  claim 35  or  claim 36  comprising contacting the gas stream with the catalytic material at a temperature of about 150° C. with a O 2 : CO ratio of about 1.5:1 and a space velocity of about 80,000/hr.  
     
     
         42 . The method of  claim 37  comprising operating under conditions in which the temperature, gas velocity and O 2 :CO ratio are related as follows: temperature=(90+x)° C., speed=(20,000+1,000x)VHSV and O 2 :CO ratio=(0.8+0.0033x):1, where x≧0.  
     
     
         43 . A method for treating a gas containing carbon monoxide, hydrogen and oxygen, comprising flowing the gas through a first flow path in a catalyst member having at least two flow paths therethrough with gas in the second flow path whereby to exchange heat between the gases in the two flow paths.  
     
     
         44 . The method of  claim 43  wherein the catalytic material is effective for the selective oxidation of carbon monoxide of the gas in the first flow path.