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

Abstract

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–Ce_0.8Zr_0.2O₂ 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–Ce_0.8Zr_0.2O₂ 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 Ce_0.8Zr_0.2O₂.