Influence of the preparation methods and redox properties of Cu/ZnO/Al2O3 catalysts for the water gas shift reaction

Abstract

Different coprecipitation sequences were used to prepare Cu/ZnO/Al2O3 catalysts for the water gas shift reaction. The interdispersion of the components of the obtained mixture of hydroxycarbonates seemed to be influenced by the coprecipitation sequence, at constant pH and temperature. High metallic copper surface area was observed when Cu2+ and Zn2+ ions were simultaneously coprecipitated. A remarkable activity was found to be related to the catalyst ability to restore the copper surface dispersion after reduction or oxidation pre-treatment. These last findings were evidenced by temperature-programmed reduction and X-ray photoelectron spectroscopy experiments.