Inert CH4vs. polarized electrodes: current trends and perspectives on methane electroactivation

Abstract

The electrochemical approach to the methane oxidation reaction (MOR) is garnering huge attention in the field of electrocatalysis within energy science and technology, aiming to selectively convert methane to value-added chemicals such as methanol, ethanol, propanol, and other methyl derivatives while minimizing CH₄ emissions at its source. Despite huge advancements at the laboratory scale, notable gaps exist that hinder the seamless conversion of methane into value-added products. In this review, the types of electrochemical methane oxidation approaches, both direct and indirect, are critically discussed along with their merits and demerits, as well as the different electrodes and electrolytes used. Various strategies focusing on electrolyte engineering (pH and concentration modulation), reaction kinetics (temperature, pressure, and electrochemical cell setup), and electrode engineering (doping, defect, interface engineering, and morphology engineering) are analysed in depth here. Additionally, several challenges associated with the MOR are highlighted, along with proposed solutions to address them. The role of modern tools like machine learning and artificial intelligence is also discussed in detail to show how further rapid advancement can be made in the MOR, which might help bridge the gap between the laboratory achievements and industrially relevant operation conditions.