Effect of Structural and Lattice Oxygen Changes on the Properties of CuO/CeO2 Catalysts for High-Temperature Water-Gas Shift of H2-rich Coal-Derived Synthesis Gas

摘要

A series of CeO2-based Cu catalysts was synthesized by the co-precipitation method. BET, N2O decomposition, XRD, TEM, EDS, Raman spectroscopy, H2-TPR, and XPS were used to characterize the catalysts. The catalytic activity was tested in terms of CO conversion and H2 selectivity in a H2-rich coal-derived synthesis gas. The effects of the copper content and the calcination temperature on the catalytic activity were investigated. A strong surface structure-activity relationship in the water-gas shift (WGS) reaction was observed for all the catalyst samples. With increasing CuO loading, the portion of finely dispersed CuO nanoparticles decreased. By contrast, increasing calcination temperature reduced the BET surface area and reducibility, as induced by CuO agglomeration, resulting in a negative effect on H2 production. The distinctive dependence of the WGS activity on the surface lattice oxygen and active oxygen vacancy of the examined solids was observed and investigated for all the CuO/CeO2 catalysts.