A Hierarchical Nanoporous PtCu Alloy as an Oxygen-Reduction Reaction Electrocatalyst with High Activity and Durability

Abstract A hierarchical nanoporous (HNP) PtCu alloy was successfully fabricated by two‐step dealloying of a well‐designed PtCuAl precursor alloy combined with an annealing operation. The as‐made PtCu alloy has an interconnected hierarchical network architecture with controllable bimodal ligament/pore distributions obtained by adjusting the annealing temperature and the redealloying time. HNP‐PtCu exhibits superior specific and mass activities for the oxygen‐reduction reaction (ORR) compared with single‐modal nanoporous PtCu and commercial Pt/C catalysts. More importantly, the HNP‐PtCu alloy shows much higher structure stability with less loss of the electrochemical surface area of Pt and ORR activity upon long‐term potential scans in acid solution. The excellent electrocatalytic performance for ORR makes the HNP‐PtCu alloy attractive as efficient cathode electrocatalysts in fuel‐cell‐related technologies.