Preferential oxidation of CO in excess H ₂ over CeO ₂/CuO catalyst: Effect of calcination temperature

Different from the classical configuration CuO/CeO ₂ catalyst, the inverse configuration CeO ₂/CuO catalyst (atomic ratio of Ce/Cu = 10/100) was prepared by impregnation method. Five calcination temperatures were selected to investigate the interaction between CeO ₂ and CuO support. It is found that as calcination temperature increased from 500 to 900°C, sintering of CeO ₂ 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 H ₂ stream.