Catalyst-free photochemical CO 2 hydrogenation to CO and CH 4 conversion to C 2 H 6

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 CO 2 hydrogenation to CO and transformation of CH 4 to H 2 and C 2 H 6 . It was demonstrated that the reactions could proceed efficiently at catalyst-free and ambient conditions, and water could further promote the transformation of CH 4 . 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. , CO 2 hydrogenation or CH 4 conversions triggered by high-energy photons under ambient conditions, which have promising potential in applications due to some obvious advantages.