CO₂/carbonate-mediated electrochemical water oxidation to hydrogen peroxide.

ABSTRACT: Electrochemical water oxidation reaction (WOR) to hydrogen peroxide (H₂O₂) via a 2e^- pathway provides a sustainable H₂O₂ synthetic route, but is challenged by the traditional 4e^- counterpart of oxygen evolution. Here we report a CO₂/carbonate mediation approach to steering the WOR pathway from 4e^- to 2e^-. Using fluorine-doped tin oxide electrode in carbonate solutions, we achieved high H₂O₂ selectivity of up to 87%, and delivered unprecedented H₂O₂ partial currents of up to 1.3 A cm^-2, which represents orders of magnitude improvement compared to literature. Molecular dynamics simulations, coupled with electron paramagnetic resonance and isotope labeling experiments, suggested that carbonate mediates the WOR pathway to H₂O₂ through the formation of carbonate radical and percarbonate intermediates. The high selectivity, industrial-relevant activity, and good durability open up practical opportunities for delocalized H₂O₂ production.

SUBMITTER: Fan L 

PROVIDER: S-EPMC9106728 | biostudies-literature | 2022 May

REPOSITORIES: biostudies-literature