Facet-Controlled Metal Alloy Electrocatalysts for Oxygen Reduction Reaction: Unconventional Post Treatment of Pt_3Ni Octahedral Catalysts for Enhanced Activity

摘要

The paper describes a ligand exchange approach to the post-synthesis treatment of solution phase produced Pt_3Ni octahedral electrocatalysts for the reduction of oxygen. Ligand exchange using short-chain amine is shown to be critical for achieving high activity towards the oxygen reduction reaction (ORR). Unlike Pt or other ORR electrocatalysts without well-defined (111) surface, the maximum ORR activity for Pt_3Ni octahedral catalysts was achieved at a low annealing temperature of 230 °C. This study indicates a different thermal treatment strategy is required for Pt alloy electrocatalysts with well-defined (111) surface, such as octahedral, tetrahedral, and icosahedral nanoparticles.