Electrocatalytic conversion of methane to ethanol by ultrathin WO3 nanosheets: Oxygen vacancy engineering

•Ultrathin WO3 nanosheets with controlled oxygen vacancies (Ov) were synthesized.•CH4 electrocatalytic conversion to ethanol was achieved.•A record-breaking ethanol yield rate of 125,090 μmol gcat−1 h−1 was realized.•Roles of Ov were studied using in-situ Raman and DFT calculation. Electrocatalytic conversion of CH4 into valuable liquid products is an attractive strategy for utilization of natural gas, however, it was still constrained by low product yields. Herein, ultrathin WO3 nanosheets with adequate oxygen vacancies (Ov) as robust electrocatalysts for highly efficient CH4 conversion to ethanol were synthesized. Using the optimized sample, the ultrahigh ethanol yield and selectivity of 125,090 μmol gcat−1 h−1 and 99.4% are achieved within 8 h at low potential of 1.2 V vs. RHE, both of which outperform the previous reports as we know. The corresponding ethanol Faradic efficiencies is 50.7%. In-situ Raman spectra and density functional theory calculation reveal that Ov effectively enable CH activation and CC coupling, and eventually promotes the electrocatalytic activity and ethanol selectivity for CH4 conversion. This work provides a constructive avenue for designing electrocatalysts with both high activity and selectivity to realize CH4 conversion. [Display omitted]