Electrocatalytic conversion of methane: Recent progress and future prospects

Methane has gained significant attention due to its abundant reserves and notable greenhouse effect. Electrocatalytic conversion of methane is an efficient and green pathway proceeding under mild conditions. However, the low solubility of methane in aqueous electrolytes imposes mass transfer limitations, leading to low current densities in electrocatalytic reactions and hindering large-scale production. This paper discusses the recent progress in quite a few aspects of electrocatalytic conversion of methane. Firstly, the reaction mechanisms involved in methane electrocatalysis are summarized, including dehydrogenation and C–H bond cleavage mediated by the active species. Next, we discuss how to promote electrochemical methane conversion regarding both the reaction process and mass transfer from the perspective of chemical engineering. Considerable efforts have been done to enhance the reaction process, including developing efficient electrocatalyst and devices. Meanwhile, the enhancement of transport processes via, e.g. improving the solubility of methane and modification on the transport area and distance, also facilitates more efficient methane conversion. Finally, an outlook on future development challenges is provided.