In situ surface reconstruction of a Ni-based perovskite hydroxide catalyst for an efficient oxygen evolution reaction

Abstract

One core reaction involved in many electrochemical energy conversion systems is the oxygen evolution reaction (OER), which usually dominates the overall polarization loss due to its sluggish kinetics. Activating O₂ electrocatalysis on the catalyst surface requires effective regulation of the surface spatial and electronic structure to facilitate the in situ generation of active species. Here, we report an in situ surface reconstruction method to boost the activity of a Ni-based perovskite hydroxide, NiSn(OH)₆, for OER catalysis. The surface reconstruction is modulated by anodic polarization during the OER process, building a Ni³⁺-containing amorphous layer with selective Sn etching. Taking advantage of the in situ surface amorphization that facilitates the generation of active metal oxy(hydroxide) species, a significant performance enhancement is achieved on NiSn(OH)₆. Theoretical calculations further demonstrate that the Sn vacancies on the surface optimize the electronic structure of the Ni sites and promote the adsorption of the reaction intermediates.