Preferential oxidation of CO in excess H₂ over the CeO ₂/CuO catalyst: Effect of initial support

Three series of CeO₂/CuO samples were prepared by impregnation method and characterized by XRD, N₂ adsorption-desorption, temperature-programmed 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 calcination temperatures of 400 °C-600 °C. As a result, Cu(OH)₂ is better than CuO as initial support for preferential oxidation of CO in excess H ₂ (CO-PROX). The best catalytic performance was achieved on the sample calcined at 600 °C 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 °C. And the atomic ratio of Ce/Cu at 40% led to a proper reducibility for the sample as illustrated by the TPR measurements.