Improved CO-PROX selectivity of CuO/CeO2 catalysts by decorating with lanthanum via surface Cuξ+ redox site

[Display omitted] •Enhanced surface Ce3+ and Ov on La-CeO2 provide superior oxygen recycling capacity.•CuO/La-CeO2 features stable Cuξ+ sites, resulting in stronger CO adsorption.•CuO/La-CeO2 exhibits exceptional CO-PROX selectivity with trace CO outlet. Hydrogen purification is essential to satisfy the various purity requirements for different applications. Preferential oxidation of carbon monoxide (CO-PROX) is a promising strategy for removing CO from H2-rich reformate in proton exchange membrane fuel cells (PEMFCs). Nonetheless, the large proportion of H2 production via methanol steam reforming (MSR) will intensify oxidation competition between H2 and CO, and the CO conversion and CO2 selectivity decrease considerably with increasing temperature. The tolerance of the PEMFCs against the CO species absorbed upon the surface presents the biggest dilemma. This work modified the conventional CuO/CeO2 catalyst in the CO-PROX by doping the support with lanthanum (La). CuO/La-CeO2 catalyst can effectively eliminate CO (