Cu/CeO 2 Catalyst for Water-Gas Shift Reaction: Effect of CeO 2 Pretreatment.

CuO/CeO2 is a kind of promising catalysts for the water-gas shift (WGS) reaction. Efforts were put in to improve its performance through modification of CeO2 support. In this study, portions of CeO2 prepared by a co-precipitation method were separately annealed at 300 °C in air, under vacuum and with H2 , and were used as supports for the fabrication of CuO/CeO2 catalysts. The physicochemical properties of the catalysts were characterized by X-ray diffraction, N2 -physisorption, inductively coupled plasma, Raman spectroscopy, CO2 temperature-programmed desorption, and H2 temperature-programmed reduction techniques. The relation between catalytic performances and physicochemical properties of the CuO/CeO2 catalysts were discussed. Among the three catalysts, the one with CuO supported on H2 -reduced CeO2 shows the highest catalytic activity, mainly due to strong CuO-CeO2 synergetic interaction and high concentration of Frenkel-type oxygen vacancies. The superior catalytic activities can also be attributed to the Cu0 crystals of small size and the oxygen vacancies in non-stoichiometric CeO2-x .