Preparation and characterization of Cu-Ce-La mixed oxide as water-gas shift catalyst for fuel cells application

Abstract

Cu-Ce-La mixed oxides were prepared by three precipitation methods (coprecipitation, homogeneous precipitation, and deposition precipitation) with variable precipitators and characterized using X-ray diffraction, BET, temperature-programmed reduction, and catalytic reaction for the water-gas shift. The Cu-Ce-La mixed oxide prepared by coprecipitation method with NaOH as precipitator presented the highest activity and thermal stability. Copper ion substituted quadrevalent ceria entered CeO 2 (111) framework was in favor of activity and thermal stability of catalyst. The crystallinity of fresh catalysts increased with the reduction process. La 3+ or Ce 4+ substituted copper ion entered the CeO 2 framework during reduction process. The coexistence of surface copper oxide (crystalline) and pure bulk crystalline copper oxide both contributed to the high activity and thermal stability of Cu-Ce-La mixes oxide catalyst.