A Sustainable Strategy to Reduce Net Methane Emissions from Thermokarst Lakes by Electrochemical Methane Partial Oxidation

Global warming increases methane emissions from Arctic permafrost, which in turn reaccelerates global warming, creating a vicious cycle. Addressing this issue requires innovative solutions, such as electro-assisted methane partial oxidation (EMPO), which can provide an on-site facility for sustainable methane emission reduction in permafrost. In this study, a Co singe-atom catalyst was synthesized as an oxygen reduction reaction (ORR) catalyst that can be practically applied to stand-alone EMPO systems. To address performance degradation and cold weather freezing due to flooding of the electrodes, the hydrophobic polytetrafluoroethylene was mixed into a catalyst layer to regulate the microenvironment near cathodes. Furthermore, hydrophobic cathodes offer a pathway for nonpolar gases to increase the local concentration of methane. The enhanced local methane concentration, combined with an efficient ORR catalyst, yields 8 mmol gcat-1 formic acid at a low potential bias. Remarkably, the EMPO system exhibits a consistent production of air and is highly stable.