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

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 (O-1(2)) typically manifests a mild redox capacity with a high selectivity to attack organic substrates. Peroxomonosulfate (PMS) favors to produce oxidative species O-1(2) during the photocatalytic reactions. Thus, combining atomic Au as co-catalyst and O-1(2) 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. (C) 2021 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.

Automated summary

The combination of gold as co-catalyst and singlet oxygen as oxidant is an effective strategy for selectively converting methane. Atomically dispersed Au on WO3 showed enhanced visible light photocatalytic conversion of CH4, with a high selectivity. Investigation of the radicals-pathway mechanism of methane coupling and theoretical calculations on the electronic structure of Au/WO3 were conducted for a better understanding of the process.