Bionic Design of Ni4+ Lewis Acid Site Based on Selective Seawater Oxidation

Abstract The side reaction caused by chloride ions and the toxicity to the active site have always been the hindrance to the electrocatalyst of the oxygen evolution reaction (OER) for seawater splitting. Herein, inspired by the early flowering of damaged plants, we designed a catalyst rich in oxygen vacancies (O vac ) and proved that O vac can accelerate the formation of Ni 3+ and further oxidize it to Ni 4+ , which we named as the “ripening” mechanism of O vac . O vac reduces the hydrogen proton desorption energy by regulating local charge redistribution, thus realizing the rapid transformation of Ni 2+ →Ni 3+ →Ni 4+ . Meanwhile, the hard Lewis acid Ni 4+ has strong selectivity to OH − , avoiding the competitiveness and corrosiveness of chloride ions in seawater. This work provides an effective strategy for the simple and rapid construction of self‐rebuilding high‐valence Ni 4+ electrocatalysts, and is expected to provide guidance for the development of seawater electrolysis.