Activity–Stability Relationship in Au@Pt Nanoparticles for Electrocatalysis

Abstract

Despite breakthroughs in the activity of electrocatalysts for the oxygen reduction reaction (ORR), the development of nanoscale ORR electrocatalysts is still hindered by their instability. Here, to bridge the functional link between activity and stability, well-controlled Au@Pt (core@shell) nanoparticles are investigated. In situ monitoring of atomic dissolution and physicochemical analysis in conjunction with theoretical calculations reveal that the atomic-level stability of Au@Pt nanoparticle is attributed to the low surface coverage of OH and oxide on Pt, balancing between strain and ligand effect of Au at the interface. Considering the relationships in activity-stability-oxophilicity, the functional links between activity and stability in the ORR are discussed, and the regulation of oxophilicity is suggested as a guideline for designing highly active and durable electrocatalysts for fuel cell applications.