Tailoring of Pd–Pt bimetallic clusters with high stability for oxygen reduction reaction

Abstract

The composition-dependent equilibrium structure and thermal stability of Pd–Pt clusters with the size of 55 atoms, and CO, O, OH, and O₂ adsorption on these clusters have been studied using molecular simulation based on the Gupta empirical potential and density functional theory (DFT) calculations. It is found that Pd₄₃Pt₁₂ with a three-shell onionlike structure (TS-cluster) exhibits the highest relative stability in both DFT and Gupta levels and also the highest melting point at the Gupta level among these Pd–Pt clusters. In addition, the Pd₄₃Pt₁₂ TS-cluster possesses the weakest CO, O, OH, and O₂ adsorption strength, compared to the Pt₅₅, Pd₅₅, and Pd₁₃Pt₄₂ clusters, indicating good catalytic activities toward the oxygen reduction reaction (ORR) among these Pd–Pt clusters considered. We expect that this kind of DFT-guided strategy by controlling the composition could provide a simple way for possibly searching new electrocatalysts.