Effects of Support on Performance of Methanol Oxidation over Palladium-Only Catalysts

Two kinds of palladium-only catalysts loaded mesoporous beta zeolite (Pd/beta) and alumina (Pd/Al2O3) have been successfully prepared by the impregnation method and characterized using nitrogen adsorption–desorption, XRD, TEM, H2-TPR, CO2-TPD, and XPS. Catalytic activities of the catalysts for methanol oxidation were investigated with CO coexisting. The results showed that the different support determines the metal-support interaction, thus affecting the catalytic behavior. For Pd/beta, the strong basicity and better reductive ability are beneficial for improving the reaction rate of catalytic oxidation for methanol. And the palladium species with a higher oxidation state is responsible for excellent catalytic conversion of methanol and CO resistance. Compared to Pd/Al2O3, the T50, T90, and ΔT on Pd/beta catalyst are 145 °C, 160 °C, and 15 °C, respectively, in the case of CO present, which decreased by 45 °C, 91 °C, and 46 °C. So beta zeolite, as a new type of catalyst support material, has a good application prospect to meet the practical needs for emission purification of methanol-gasoline vehicles.