Preparation of ceria-alumina and |catalytic activity of gold catalyst supported on ceria-alumina for water gas shift reaction

Ceria-alumina composite oxides with different ceria loadings (5%, 10%, 20%, 25%, and 30%) were prepared by impregnation method and deposition-precipitation method, respectively. Gold catalysts supported on these oxides were used to water gas shift reaction. All samples were characterized by nitrogen adsorption, X-ray diffraction (XRD), transmission electron microscopy (TEM) and hydrogen temperatureprogrammed reduction (H₂-TPR). It is found that the preparation method and calcination temperature of ceria-alumina oxides have a marked influence on their surface areas, porous structures and the catalytic performances of supported gold catalysts for water gas shift reaction. Ceria-alumina oxides prepared with impregnation method gave larger ceria particle size and high catalytic activity than those prepared with depositionprecipitation method. Gold catalyst supported on 20%CeO₂-Al₂O₃ oxide calcined at 500℃ showed the highest activity. CO conversion reached 78.1% at 250℃ and atmospheric pressure.