A crucial role for the CeO2-ZrO2 support for the low temperature water gas shift reaction over Cu-CeO2-ZrO2 catalysts

摘要

A co-precipitation method was employed to prepare Cu dispersed on CeO2, ZrO2 and CeO2-ZrO2 supports to obtain catalysts useful for the low temperature water gas shift (WGS) reaction. To optimize the Cu-CeO2-ZrO2 catalysts, the CeO2/ZrO2 ratio was systematically changed. The cubic phase Cu-Ce0.8Zr0.2O2 catalyst exhibited the highest turnover frequency and the lowest activation energy among the catalysts tested and its CO conversion was maintained without significant loss during the reaction for 100 h. The enhanced catalytic activity and stability of the co-precipitated Cu-Ce0.8Zr0.2O2 was mainly attributed to an enhanced oxygen mobility and a strong resistance against the sintering of Cu, resulting from a large amount of defect oxygen and the strong interaction between CuO and cubic phase Ce0.8Zr0.2O2.