Different from the classical configuration CuO/CeO2 catalyst,the inverse configuration CeO2 /CuO catalyst （atomic ratio of Ce/Cu=10/100） was prepared by impregnation method.Five calcination temperatures were selecte...Different from the classical configuration CuO/CeO2 catalyst,the inverse configuration CeO2 /CuO catalyst （atomic ratio of Ce/Cu=10/100） was prepared by impregnation method.Five calcination temperatures were selected to investigate the interaction between CeO2 and CuO support.It is found that as calcination temperature increased from 500 to 900 C,sintering of CeO2 particles on the support occurred together with the diffusion of a portion of Ce 4＋ ions into CuO crystals,forming solid solution.Formation of interface complex Ce-O-Cu was suggested by TPR measurements.The catalyst calcined at 700 C gives the highest activity for preferential oxidation of CO in excess H2 stream.展开更多
Three series of CeO2/CuO samples were prepared by impregnation method and characterized by XRD, N2 adsorption-desorption, temperatureprogrammed reduction （TPR）, XPS and TEM techniques. In comparison with the samples...Three series of CeO2/CuO samples were prepared by impregnation method and characterized by XRD, N2 adsorption-desorption, temperatureprogrammed reduction （TPR）, XPS and TEM techniques. In comparison with the samples prepared with CuO as initial support, the samples with Cu（OH）2 as initial support have higher reducibilities and smaller relative TPR peak areas, and also larger specific surface areas at calcina- tion temperatures of 400 ℃--600 ℃. As a result, Cu（OH）2 is better than CuO as initial support for preferential oxidation of CO in excess H2 （CO-PROX）. The best catalytic performance was achieved on the sample calcined at 600 ℃ and with an atomic ratio of Ce/Cu at 40%. XPS analyses indicate that more interface linkages Ce-O-Cu could be formed when it was calcined at 600 ℃. And the atomic ratio of Ce/Cu at 40% led to a proper reducibility for the sample as illustrated by the TPR measurements.展开更多
文摘Different from the classical configuration CuO/CeO2 catalyst,the inverse configuration CeO2 /CuO catalyst （atomic ratio of Ce/Cu=10/100） was prepared by impregnation method.Five calcination temperatures were selected to investigate the interaction between CeO2 and CuO support.It is found that as calcination temperature increased from 500 to 900 C,sintering of CeO2 particles on the support occurred together with the diffusion of a portion of Ce 4＋ ions into CuO crystals,forming solid solution.Formation of interface complex Ce-O-Cu was suggested by TPR measurements.The catalyst calcined at 700 C gives the highest activity for preferential oxidation of CO in excess H2 stream.
文摘Three series of CeO2/CuO samples were prepared by impregnation method and characterized by XRD, N2 adsorption-desorption, temperatureprogrammed reduction （TPR）, XPS and TEM techniques. In comparison with the samples prepared with CuO as initial support, the samples with Cu（OH）2 as initial support have higher reducibilities and smaller relative TPR peak areas, and also larger specific surface areas at calcina- tion temperatures of 400 ℃--600 ℃. As a result, Cu（OH）2 is better than CuO as initial support for preferential oxidation of CO in excess H2 （CO-PROX）. The best catalytic performance was achieved on the sample calcined at 600 ℃ and with an atomic ratio of Ce/Cu at 40%. XPS analyses indicate that more interface linkages Ce-O-Cu could be formed when it was calcined at 600 ℃. And the atomic ratio of Ce/Cu at 40% led to a proper reducibility for the sample as illustrated by the TPR measurements.
