Constructing an Atomic Layer Pt Electrocatalyst with a Concave Curved Surface for the Oxygen Reduction Reaction

Abstract One of the strategic objectives in fuel cell technologies is to develop oxygen reduction reaction (ORR) catalysts with high activity, stability and, moreover, a low Pt loading. Computational results have indicated that surfaces or nanostructures with concave defects exhibit higher ORR activity than convex ones. Here, atomic layers of Pt were epitaxially coated on nanoporous gold (NPG) for the unique surface structure, both with convex or concave curvatures of the NPG. Outstanding ORR activities were revealed on Pt overlayers who copied the substrate's surface features. Furthermore, ascribed to the adverse impacts of tensile Pt lattice on gold, an optimized specific activity has been found as a function of the increasing Pt atomic layers. Pt coating with three atomic layers on NPG (NPG−Pt3) shows the best specific activity with an approximate 9‐fold improvement with respect to commercial Pt/C, as well as a 10‐fold enhancement in mass activity at 0.9 V versus a reversible hydrogen electrode.