Three-phase interface engineering for enhanced acidic CO2 electroreduction

The electrocatalytic carbon dioxide reduction reaction (CO 2 RR) provides a promising and feasible approach for utilizing CO 2 as a resource and transforming the energy structure of the chemical industry. Compared with alkaline/neutral electrocatalytic systems, acidic environments not only effectively inhibit product crossover but also reduce the energy consumed for reactant regeneration. However, the dominant hydrogen evolution reaction (HER) and acid corrosion in an acidic solution seriously threaten the selectivity and stability of the CO 2 RR. To address these challenges, an efficient CO 2 RR can be achieved by regulating the mass transfer process and microenvironment through gas–solid–liquid three-phase interface engineering. This review summarizes the recent progress in acidic CO 2 RR research and focuses on optimization strategies for gas–liquid, gas–solid, and solid–liquid interfaces. We discuss the key challenges associated with each phase interface and outline innovative research directions to optimize the selectivity, activity, and stability of the acidic electrocatalytic CO 2 RR for industrial application.