Modification of Co/Al2O3 with Pd and Ce and their effects on benzene oxidation

Palladium and cerium oxide promoted Co/Al2O3 catalysts were prepared and used for oxidation of benzene. Influence of Pd, Ce and Co/Ce molar ratios on the properties and catalytic performance was investigated. The results indicated that addition of palladium and cerium oxide could provide active oxygen species to cobalt oxide and make Co3O4 particles better dispersed on Al2O3, thus enhancing oxidation ability of the catalyst. High catalyst activity is mainly attributed to better dispersed Co3O4 on Al2O3, smaller Co3O4 crystallites and larger CeO2 crystallites which can strengthen the interaction among PdO, CeO2 and Co3O4.

► The Co/Al2O¬3 catalyst with Pd and Ce addition exhibits high activity.
► Pd/Co-Ce/Al2O3 with a Co/Ce mole ratio of 6 owns the highest activity.
► High activity is attributed to better dispersed Co3O4 and larger CeO2 crystallites.