Mechanism of CO preferential oxidation catalyzed by CunPt (n = 3–12): a DFT study

The CO preferential oxidation reaction (PROX) is particularly well suited for hydrogen purification for proton exchange membrane fuel cell applications. In this work, the mechanism of CO-PROX catalyzed by Cu n Pt ( n = 3–12) clusters has been studied by density functional theory calculations. The calculated results indicate that the most favored adsorption site of H 2 for all clusters is on the Pt sites, and O 2 prefers to bind on Cu sites and CO bind on Pt sites. The lowest energy barrier for hydrogen dissociation is 0.02 eV. Smaller H–Pt bond length of Cu n PtH 2 corresponds to larger H–H bond length. CO-PROX occurs via the main intermediates of COOH and OH. Cu 6 Pt is proposed as the most effective catalyst for CO-PROX. To understand the high catalytic activity of Cu n Pt clusters, the nature of the interaction between adsorbate and substrate is also analyzed by detailed electronic local density of states. These findings enrich applications of Cu-based materials to the field of high-activity catalysts.