Sustainable Synthesis of Concentrated Formate via CO2 Electrolysis Integrated with Cl2 Formation

Abstract Integrating CO 2 electrolysis with an industrially relevant anodic reaction enhances the economic feasibility and reduces carbon emissions in practical operations. In this study, we present an electrosynthesis strategy that integrates the CO 2 reduction reaction to produce concentrated formate solution with the Cl 2 formation in cation exchange membrane‐based electrolyzers, scaling from 1 to 100 cm 2 electrode areas. Our process, equipped with two automated pH regulation strategies, achieved selectivities over 80% for formate and 95% for chlorine in a 25 cm 2 electrolyzer. Additionally, it demonstrated the ability to achieve formate concentrations up to 5.4 M during extended operation periods, establishing a new benchmark for electrochemical formate/formic acid synthesis. Techno‐economic assessment and life cycle assessment further validated the process' sustainability, demonstrating a realistic path to profitability for valuable chemical production from CO 2 even without considering potential subsidies and carbon taxes.