Light-based catalyst-free conversion of CH4 and CO2

The photon-mediated conversion of CH 4 and CO 2 represents a green and sustainable route for producing transportation fuels and chemicals. Here we report an innovative, catalyst-free strategy for the conversion, by light, of CH 4 and CO 2 into CO/H 2 and C 2 H 6 . High-energy photons with a wavelength of 185 nm were found to initiate the reaction, and the additional use of photons with different energies at longer wavelengths further improved the reaction efficiency. In particular, the combination of 185-nm and 200–1,100-nm photons enabled CO, H 2 and C 2 H 6 production rates of 3.1 mmol m −3  h −1 , 1.93 mmol m −3  h −1 and 2.53 mmol m −3  h −1 , respectively. Moderate addition of H 2 O was found to aid the reaction considerably. Moreover, a total gas conversion of 1.51% (24 h) was achieved in experiments simulating an oxygen-free environment. This work opens up a promising route for producing fuels and chemicals using CH 4 and CO 2 without the use of any catalysts, under ambient conditions.