Physicochemical characterization and catalytic performance of 10% Ag/CeO 2 catalysts prepared by impregnation and deposition–precipitation

Abstract Two silver–cerium oxide samples (Ag 10 wt.%) were prepared by two different methods: impregnation and deposition–precipitation. The XRD, EPR, XPS, and TPR techniques were used for physicochemical characterization. Catalysts were tested in C3H6 , CO, and carbon black oxidation reactions . The impregnated catalyst showed better performance compared to the one prepared by deposition–precipitation in the different reactions. The EPR technique allowed the identification of three different Ag 2+ sites in the impregnated solid along with the distinction of the Ag2+ isotopes ( 107Ag2+ and 109Ag2+) ions. The impregnated catalyst reduced at lower temperatures compared to the one prepared by deposition–precipitation. The catalytic activity of the impregnated solid was attributed to the presence of Ag2+ species that enhance the redox potential of the solid by creating three different redox couples: Ag2+/Ag+, Ag2+/Ag0, and Ag+/Ag0.