Electrocatalytic CO2 reduction reaction (CO2RR) is crucial for carbon recycling and neutrality, yet its efficiency is hampered by the high-energy oxygen evolution reaction (OER). Paired electrolysis has emerged as a promising strategy to simultaneously lower energy consumption and enhance product value by replacing OER with value-added organic oxidation reactions. This review summarizes recent advances in CO2RR coupled with alternative anode reactions. It begins with CO2RR mechanisms and product control strategies, analyzing influences of catalyst properties, electrolyte environments, and reaction conditions. Then, the core integration strategies of paired electrolysis systems are elaborated in terms of selection and integration of anode reaction, thermodynamic/kinetic matching, electron-proton transfer synergy, pH compatibility, system stability, and optimal reactor design. A detailed review of the application of heterogeneous electrocatalyst pairs and homogeneous electrocatalyst pairs in coupled systems from the perspective of electrode material design is presented, and the relationship sbetween their structure-activity and synergistic mechanism is also discussed. Finally, the existing technical problems in this field are summarized, including the bottlenecks of product value addition, system energy consumption, system stability, and large-scale integration. This review provides theoretical guidance and technical reference for designing an efficient system of paired electrolysis in the future.
Wu et al. (Sat,) studied this question.