Visible-light driven room-temperature coupling of methane to ethane by atomically dispersed Au on WO3

Abstract Gold (Au) as co-catalyst is remarkable for activating methane (CH4), especially atomically dispersed Au with maximized exposing active sites and specific electronic structure. Furthermore, singlet oxygen (1O2) typically manifests a mild redox capacity with a high selectivity to attack organic substrates. Peroxomonosulfate (PMS) favors to produce oxidative species 1O2 during the photocatalytic reactions. Thus, combining atomic Au as co-catalyst and 1O2 as oxidant is an effective strategy to selectively convert CH4. Herein, we synthesized atomically dispersed Au on WO3 (Au/WO3), where Au was in the forms of single atoms and clusters. At room temperature, such Au/WO3 exhibited enhanced photocatalytic conversion of CH4 to CH3CH3 with a selectivity, up to 94%, under visible light. The radicals-pathway mechanism of CH4 coupling has also been investigated through detection and trapping experiment of active species. Theoretical calculations further interpret the electronic structure of Au/WO3 and tip-enhanced local electric field at the Au sites for promoting CH4 conversion.