Direct and Selective Photocatalytic Oxidation of CH 4 to Oxygenates with O 2 on Cocatalysts/ZnO at Room Temperature in Water

Direct conversion of methane into methanol and other liquid oxygenates still confronts considerable challenges in activating the first C–H bond of methane and inhibiting overoxidation. Here, we report that ZnO loaded with appropriate cocatalysts (Pt, Pd, Au, or Ag) enables direct oxidation of methane to methanol and formaldehyde in water using only molecular oxygen as the oxidant under mild light irradiation at room temperature. Up to 250 micromoles of liquid oxygenates with ∼95% selectivity is achieved for 2 h over 10 mg of ZnO loaded with 0.1 wt % of Au. Experiments with isotopically labeled oxygen and water reveal that molecular O2, rather than water, is the source of oxygen for direct CH4 oxidation. We…

• NN
  National Natural Science Foundation of China

  Awards: 51872091, 21633004
• CS
  China Scholarship Council

  Award: 201606320239
• HU
  Hokkaido University
• JS
  Japan Society for the Promotion of Science

  Award: JP18H02065