PtCoNi Alloy Nanoclusters for Synergistic Catalytic Oxygen Reduction Reaction

Alloying is a viable approach to alter the local and overall structure of metallic nanocatalysts, thereby offering new possibilities to tune catalytic activities and selectivity of alloy nanoclusters. However, systematic study of the effects of alloying on the catalytic reaction mechanism is still lacking. Here, a systematic study of the oxygen reduction reaction (ORR) on the 55-atom Pt-covered alloy nanoclusters was conducted. The addition of Co atoms not only can lead to different reaction mechanism for ORR, e.g., from the hydroperoxyl dissociation to the oxygen dissociation, but also can increase the catalytic activity of the Pt-covered alloy nanoclusters. The energy barrier in the reaction-determining step and the excess energy of the 55-atom Pt-covered alloy nanoclusters suggest that among the 55-atom Pt-covered bimetallic and tri-metallic alloy nanoclusters, the Pt42Co12Ni1 tri-metallic catalyst possesses the highest catalytic activity and the best structural stability. Based on the “descriptor” (ΔG...