Kirkendall effect-driven formation of hollow PtNi alloy nanostructures with enhanced oxygen reduction reaction performance

Abstract

The design of Pt-based cathode catalyst for the oxygen reduction reaction (ORR) is critical for fabricating high-performance polymer electrolyte membrane fuel cells. In this study, hollow PtNi alloy nanostructures (h-PtNi/C-X) deposited on a carbon black support are prepared using a facile synthesis method at various pH value (X). The degree of alloying of the hollow nanostructures is modulated with increasing pH. Among these h-PtNi/C cata-lysts, h-PtNi/C-11 exhibits superior ORR activity (five-fold mass activity and higher power density) and improved durability both in half and unit cells, compared to a commercial Pt/C catalyst.