Carboxylated Hexagonal Boron Nitride/Graphene Configuration for Electrosynthesis of High‐Concentration Neutral Hydrogen Peroxide

Abstract

AbstractThe electrosynthesis of hydrogen peroxide (H2O2) via two‐electron (2e−) oxygen (O2) reduction reaction (ORR) has great potential to replace the traditional energy‐intensive anthraquinone process, but the design of low‐cost and highly active and selective catalysts is greatly challenging for the long‐term H2O2 production under industrial relevant current density, especially under neutral electrolytes. To address this issue, this work constructed a carboxylated hexagonal boron nitride/graphene (h‐BN/G) heterojunction on the commercial activated carbon through the coupling of B, N co‐doping with surface oxygen groups functionalization. The champion catalyst exhibited a high 2e− ORR selectivity (>95 %), production rate (up to 13.4 mol g−1 h−1), and Faradaic efficiency (FE, >95 %). The long‐term H2O2 production under the high current density of 100 mA cm−2 caused the cumulative concentration as high as 2.1 wt %. The combination of in situ Raman spectra and theoretical calculation indicated that the carboxylated h‐BN/G configuration promotes the adsorption of O2 and the stabilization of the key intermediates, allowing a low energy barrier for the rate‐determining step of HOOH* release from the active site and thus improving the 2e− ORR performance. The fast dye degradation by using this electrochemical synthesized H2O2 further illustrated the promising practical application.