Site-Specific Activity of Pt Single Crystal Surfaces for Oxygen Reduction Reaction

Abstract

Development of industrial electrocatalysts with improved performance strongly relies on the fundamental understanding of the model systems. Pt(111) surface is probably the simplest, the most fundamental and thus also the most classic model systems for studying the hydrogen and oxygen electrocatalysis, among others. While the wide terrace has long been taken for granted to be the playground of the electrocatalytic reactions, here we demonstrate that such a hypothesis is far incomplete. By combining DFT calculations with experimental measurements, we unravel a 1-2 nm zone with 50% to 5000% activity enhancement for oxygen reduction reaction, which are induced by intrinsic strain that is generated because of the release of surface stress. We further demonstrate how this mechanistic understanding can be utilized to improve the activity of both model electrocatalysts and industrial electrocatalysts.