HClO‐Mediated Photoelectrochemical Epoxidation of Alkenes with Near 100 % Conversion Rate and Selectivity by Regulating Lattice Chlorine Cycle

Abstract Directional organic transformation via a green, sustainable catalytic reaction has attracted a lot of attention. Herein, we report a photoelectrochemical approach for highly selective epoxidation of alkenes in a salt solution using Co 2 (OH) 3 Cl (CoOCl) as a bridge of photo‐generated charge, where the lattice Cl − of CoOCl can be oxidized to generate HClO by the photo‐generated holes of BiVO 4 photoanode and be spontaneously recovered by Cl − of a salt solution, which then oxidizes the alkenes into the corresponding epoxides. As a result, a series of water‐soluble alkenes, including 4‐vinylbenzenesulfonic acid sodium, 2‐methyl‐2‐propene‐1‐sulfonic acid sodium, and 3‐methyl‐3‐buten‐1‐ol can be epoxidized with near 100 % conversion rate and selectivity. Through further inserting a MoO x protection layer between BiVO 4 and CoOCl, the stability of CoOCl−MoO x /BiVO 4 can be maintained for at least 120 hours. This work opens an avenue for solar‐driven organic epoxidation with a possibility of on‐site reaction around the abundant ocean.