Electrocatalytic conversion of methane: Mechanisms, catalyst design, and microenvironment regulation

Electrochemical methane conversion has emerged as a promising strategy for the sustainable utilization of methane under mild conditions, offering precise control over reaction pathways and compatibility with renewable electricity. This review summarizes recent advances in electrocatalytic methane conversion with a focus on mechanistic understanding, catalyst design principles, and interfacial microenvironment regulation. The fundamental challenges associated with methane activation, including the high C–H bond strength and competition with the oxygen evolution reaction, are discussed from thermodynamic and kinetic perspectives. Particular attention is given to the electronic structure of transition metal catalysts, dynamic evolution of active sites, and the role of electrolyte parameters such as pH, ion adsorption, double-layer structure, and solvent effects in governing activity and selectivity. Representative catalyst systems, especially Ni-based and oxide-derived materials, are analyzed to elucidate structure–performance relationships for selective formation of oxygenated products such as methanol, ethanol, and formic acid. In addition, system-level strategies including reactor design, pressure regulation, and integration with renewable energy are highlighted to improve energy efficiency and practical feasibility. Finally, a carbon–energy perspective is proposed, emphasizing that the primary value of methane electrocatalysis lies in its selective upgrading to value-added chemicals rather than deep oxidation or energy-intensive carbon cycling. This review provides insights and future directions for the development of efficient and sustainable electrochemical methane conversion technologies, with an emphasis on the intrinsic coordination characteristics of catalytic active centers.