Regulating reactive oxygen species balance at the WO3/BN interface for selective photooxidation of methane to methanol

Abstract

Direct photocatalytic oxidation of methane to methanol under ambient pressure offers an attractive route for C₁ valorization, yet it remains challenged by the competing requirements of activating inert C–H bonds while preventing methanol overoxidation. Here, a WO₃/BN interface is reported that addresses this activity-selectivity trade-off by regulating the balance of reactive oxygen species. Interfacial coupling with BN promotes hole extraction from WO₃ and induces electron accumulation in the WO₃ domains, thereby preferentially enhancing ·OOH generation and increasing the ·OOH/·OH ratio. The elevated ·OOH/·OH ratio balances methane activation and methanol formation. Specifically,·OOH radicals facilitate C–H bond activation in methane, whereas ·OH radicals react with the resulting *CH₃ intermediates to form methanol. The optimized WO₃/BN-1:1 catalyst achieves a CH₃OH production rate of 741.6 µmol/(g·h), nearly twice that of pristine WO₃, with a CH₃OH selectivity of 77.2% under ambient-pressure conditions. This work provides insights into regulating reactive oxygen species through interface engineering for the selective photocatalytic conversion of methane.