Progress and Perspectives for Efficient Electrochemical Carbon Dioxide Reduction to Methane.

The electrochemical carbon dioxide reduction reaction (ECO2RR) provides a promising route for synthesizing high-value chemicals and fuels for sustainable economic development. Methane, one of the potential reduction products of ECO2RR, plays a crucial role in chemical production and energy storage. Recent advancements in ECO2RR have led to significant progress in methane production. However, existing research findings remain substantially distant from practical industrial applications. In this article, the recent research progress in ECO2RR for methane production is systematically reviewed. First, the theoretical foundations of ECO2RR and the key reaction mechanisms involved in methane production are elaborated upon. Then, catalyst design strategies are summarized aimed at enhancing methane selectivity and activity, including 1) fine tuning of crystal surface, morphology, and size; (2) defects engineering; and (3) tandem catalysis. In addition, the role of modulating microenvironment is reviewed, focusing on the effects of pH, ionic effects, and CO2 concentration. Finally, some insights into the industrial application of ECO2RR to methane are presented in light of existing studies and practical needs.