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 Co2(OH)3Cl (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 BiVO4 photoanode and being spontaneously recovered by Cl of 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 MoOx protection layer between BiVO4 and CoOCl, the stability of CoOCl‐MoOx/BiVO4 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.

Highly Efficient Photoelectrochemical Alkene Epoxidation on a Dye-Sensitized Photoanode

“…Chen and Zhang also successfully accomplished the epoxidation of fat-soluble alkenes using Fe 2 O 3 photoanodes in CH 3 CN with 5% H 2 O in the presence of bromide . Recently, epoxidation of water-soluble alkenes has also been achieved on CoOCl-loaded BiVO 4 with HClO 4 as a mediator by Zhang and co-workers …”

“…23 Recently, epoxidation of water-soluble alkenes has also been achieved on CoOCl-loaded BiVO 4 with HClO 4 as a mediator by Zhang and co-workers. 28 Despite these progresses, the PEC epoxidation with high performance is still desired given the low photocurrent densities and efficiencies (IPCE < 25%). 22,23,29 Apart from the semiconductor-based PEC cells, dye-sensitized photoelectrochemical cells (DSPECs) with structural similarity to that of the natural photosynthetic system have recently been intensively investigated for solar water splitting.…”