Surface-Composition-Driven Patchy Carbon Shells Unlock High Activity and Durability in PtCu Oxygen Reduction Catalysts

Abstract

Low-temperature CO treatment induces Pt surface segregation in carbon-incorporated PtCu nanoparticles, creating Pt-rich surface domains that localize carbon growth. Subsequent high-temperature Ar treatment forms a patchy carbon shell, enabling selective near-surface Cu dealloying, boosting oxygen reduction reaction (ORR) activity while suppressing particle degradation and markedly improving durability.