Catalyst-free photochemical CO2 hydrogenation to CO and CH4 conversion to C2H6

Direct utilization of high-energy photons to drive chemical reactions presents a promising approach for the achievement of green reaction process. Herein, we developed a simple photochemical route that utilized 172 nm vacuum ultraviolet (VUV) photons as drivers for CO2 hydrogenation to CO and transformation of CH4 to H2 and C2H6. It was demonstrated that the reactions could proceed efficiently at catalyst-free and ambient conditions, and water could further promote the transformation of CH4. The reaction mechanism was proposed on the basis of control experiments. This study provides a green alternative to conventional catalytic processes for important reactions, i.e., CO2 hydrogenation or CH4 conversions triggered by high-energy photons under ambient conditions, which have promising potential in applications due to some obvious advantages.