Electrocatalytic methane oxidation via integrated design of mechanism, microenvironment, and mass transfer

Electrocatalytic methane oxidation (EMO) offers a promising approach by utilizing renewable electricity to drive electron-transfer reactions, enabling C-H bond activation and transformation into value-added chemicals at ambient temperature and pressure while offering advantages in sustainability and process control. However, challenges such as the inherent inertness of methane, its low solubility in conventional electrolytes, and tendencies toward over-oxidation severely limit catalytic efficiency. This review summarizes recent advances in EMO across three key scales. At atomic and molecular scales, mechanisms of C-H bond activation through direct electron transfer and reactive oxygen species are discussed. At the catalyst and microenvironment level, practical strategies to enhance catalysis are reviewed, including structural modification, heterogeneous interfaces, single-atom or dual-atom catalysis, and electrolyte/reactor designs. At the macroscopic transport level, methods to optimize methane transport via pressurization, electrolyte engineering, transport systems, and porous nanoarchitectures are examined. Integrating insights from reaction kinetics, catalytic microenvironments, and mass transport offers a theoretical foundation for the rational design of highly efficient, stable, and scalable electrocatalytic methane conversion.