Selective CO oxidation over CuO–CeO2 catalysts doped with transition metal oxides

CuO–CeO2 catalysts doped with transition metal oxides (ZnO, MnO2 and Fe2O3) were prepared by co-precipitation method for the selective CO oxidation. The effect of different metal oxides on the catalyst performance was examined by H2-TPR, in situ DRIFTS and XPS techniques. The results showed that CO adsorption mainly occurred on the Cu+ site. The catalytic activity at lower temperatures was related to the amounts of lattice oxygen and CO desorption. The doping of ZnO remarkably improved the catalytic activity, while Fe2O3 or MnO2 deteriorated the catalytic properties. Addition of ZnO to CuO–CeO2 catalyst stabilized the reduced Cu+ species and increased the amounts of CO adsorption and lattice oxygen. For Cu1Fe1Ce9Oδ, CO was mainly desorbed from the catalyst surface in the reversible form, which was not beneficial to the selective CO oxidation. Strong adsorption of CO on the Cu+ site at lower temperatures and the poor redox performance led to the poor catalytic property for Cu1Mn1Ce9Oδ catalyst.