Low Temperature Oxidation of Benzene Over Pd/Co3O4 Catalysts in the Electric Field

The catalytic system coupled with electric field was utilized to realize oxidation of benzene over Pd/Co3O4 catalysts at low temperature. For catalysts with 1% Pd loading, the temperature for complete conversion of benzene was substantially reduced from the 358 °C to 293 °C with electric field. The characterization results demonstrated that release of lattice oxygen in the Co3O4 spinel was enhanced with electric field, therefore reinforced the formation of PdOx from the oxidation of Pd0. DRIFT results showed that active sites [PdOx] was formed from the reaction of PdOx with O species from catalyst bulk through MvK mechanism under electric field while dissociation of gaseous oxygen that occur at relatively high temperature is necessary for the formation of active sites in conventional catalytic system. In addition, the inhibition of the produced water molecules on the catalyst activity was eliminated due to the promoted “H2O sink” effect of Co3O4 support with electric field. Based on the results and discussion, pathways of benzene oxidation over Pd/Co3O4 catalyst under electric field are revealed.