The design of alternative anodic reactions paired with electrochemical CO2 reduction

Electrochemical reduction of CO2 to produce value-added products is a promising way to utilize CO2 in the atmosphere. The anode side of the conventional carbon dioxide reduction reaction (CO2RR) system is not fully exploited, significantly limiting the overall energy conversion efficiency and economic benefits. In this review, we summarized and analyzed CO2RR-paired anodic reactions that can enhance the overall commercial profit in four broad categories, including wastewater treatment, organic synthesis, the chloride oxidation reaction and the convergent reaction. The existing scale, key factors for performance, energy efficiency and suitability to combine with CO2RR for each type of anodic reaction are all systematically compared. Finally, a detailed description of the challenges and future directions of the coupling systems are also analyzed.