Abiotic Methane Production Driven by Ubiquitous Non-Fenton-Type Reactive Oxygen Species

Abiotic CH production driven by Fenton-type reactive oxygen species (ROS) has been confirmed to be an indispensable component of the atmospheric CH budget. While the chemical reactions independent of Fenton chemistry to ROS are ubiquitous in nature, it remains unknown whether the produced ROS can drive abiotic CH production. Here, we first demonstrated the abiotic CH production at the soil-water interface under illumination. Leveraging this finding, polymeric carbon nitrides (CN) as a typical analogue of natural geobattery material and dimethyl sulfoxide (DMSO) as a natural methyl donor were used to unravel the underlying mechanisms. We revealed that the ROS, photocatalytically produced by CN, can oxidize DMSO into CH with a high selectivity of 91.5 %. Such an abiotic CH production process was further expanded to various non-Fenton-type reaction systems, such as electrocatalysis, pyrocatalysis and sonocatalysis. This work provides insights into the geochemical cycle of abiotic CH, and offers a new route to CH production via integrated energy development.