The development of superior catalysts for preferential oxidation of CO has always maintained challenging in heterogeneous catalysis. Herein it is found that the Pt-0.05/CuO-CeO2 catalyst exhibited high activity and selectivity for preferential oxidation of CO at working temperature of proton-exchange membrane fuel cells (similar to 80 degrees C). The studies indicate that the presence of platinum and cerium promote the generation of oxygen vacancy and the dissociation of O-2 molecules. Meanwhile, the introduction of platinum facilitates the reduction of copper and cerium species as well as enhances the quantity of lattice oxygen. The timely update of lattice oxygen promotes CO oxidation with the help of oxygen vacancy. The finding may provide new ideas for developing the excellent ternary catalyst for preferential oxidation of CO at the proton-exchange membrane fuel cells working temperature. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.