Research progress in C2+ products in electrocatalytic methane valorization

Abstract

As a potent greenhouse gas, the efficient value-added conversion of methane into high-value C₂₊ products (e.g., ethanol, ethylene and propanol) is crucial for achieving carbon neutrality goals. Traditional thermocatalytic routes are limited by high-temperature and high-pressure conditions and C₁-product-dominated selectivity, failing to meet the demands of a carbon resource circular economy. Electrocatalytic methane oxidation offers new opportunities for the targeted synthesis of C₂₊ compounds due to its mild reaction conditions and controllable electron transfer characteristics. However, product selectivity is constrained by the complex coupling mechanism involving C–C coupling kinetics, intermediate adsorption strength, and competitive oxidation reactions. In this perspective, we discuss reaction pathways for the electrochemical synthesis of C₂₊ products (direct C–C coupling, indirect C–C coupling, and non-coupling functionalization pathways) and outline key strategies for enhancing catalytic performance, including interface engineering, heterostructures, single-atom design, synergistic effects, and vacancy modification. Additionally, we summarize emerging catalytic reaction engineering methods to optimize reaction performance. Finally, by emphasizing the critical impact of methane sources (fossil versus biomass) on economic viability and combining techno-economic analysis (TEA) of ethanol with a comparative analysis of the electrocatalytic CO₂ reduction route, optimization directions for the reaction system were proposed. The development prospects of future high-current-density catalytic systems were also outlined, aiming to advance electrocatalytic methane conversion toward truly sustainable and economically viable applications.