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

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.