Highly Selective Photocatalytic Methane Oxidation to Methanol Using CO2 as a Soft Oxidant

Light-driven methane conversion to methanol with high selectivity is considered a challenging and promising reaction for sustainable development. Herein, Cu/CeO2 catalysts were prepared for photocatalytic methane conversion with CO2 as a soft oxidant. Methanol was the sole liquid product with a high selectivity of 96.2% and a high yield of 88.9 mu mol g-1 h-1 for the 2Cu/CeO2 catalyst. Investigation of the structure-performance relationship indicated that oxygen vacancies facilitated the trapping of photogenerated electrons and avoided carrier recombination. In addition, as a soft oxidant, CO2 can also capture photogenerated electrons to be reduced to CO and further accelerate the formation of CH3OH. A catalytic mechanism study demonstrated that methane and hydroxyl were oxidized by photogenerated holes to center dot CH3 and center dot OH, respectively, and thus, methanol was generated through the combination of center dot CH3 and center dot OH.

Automated summary

Light-driven methane conversion to methanol with high selectivity was achieved using Cu/CeO2 catalysts with CO2 as a soft oxidant. The catalyst showed a high selectivity of 96.2% and a high yield of 88.9 mu mol g-1 h-1 for methanol production. Oxygen vacancies in the catalyst facilitated electron trapping and reduced carrier recombination, while CO2 acted as a soft oxidant and accelerated methanol formation.