Integrating Nickel-Nitrogen Doped Carbon Catalyzed CO2 Electroreduction with Chlor-Alkali Process for CO, Cl2 and KHCO3 Production with Enhanced Techno-Economics

Abstract Typically, CO2 electroreduction is coupled with oxygen evolution reaction (OER), which is highly energy consuming, and also costs alkalis formed at the cathode. Here, we use chlorine evolution reaction (CER), instead of OER, to integrate with CO2 electroreduction mediated by an efficient metal-nitrogen doped carbon catalyst derived from the mixture of nickel porphyrin and commercial carbon black. The combined system was evaluated in two electrolyzer configurations that have been adopted in the chlor-alkali process to produces CO, Cl2, and KHCO3 simultaneously. To allow continuous operation, we designed a continuously operating system to collect produced KHCO3 in a precipitate tank with improved techno-economics and efficient CO2 utilization. Also, it could serve as an environmental-friendly alternative to the Solvay process for soda production. This work may provide a new strategy for the design of CO2 electrolysis systems with better economic viability.