Kilowatt-scale tandem CO2 electrolysis for enhanced acetate and ethylene production

Abstract

The conversion of carbon dioxide (CO2) into valuable chemicals is a key strategy for carbon utilization. Although tandem CO2 electrolysis has shown promise, it has been largely confined to watt-scale studies and larger-scale studies are needed to accelerate commercialization. In this work, we demonstrate a tandem CO2 electrolyzer engineered for the production of multicarbon products, acetate and ethylene, at the kilowatt (kW) scale. Here, from insights gained at the watt scale, we have successfully designed and operated a 1,000 cm2 CO electrolyzer at 0.71 kW and a 500 cm2 CO2 electrolyzer at 0.40 kW. The kW-scale CO electrolyzer stack demonstrated a stable current of 300 A over 125 h, yielding 98 l of 1.2 M acetate at 96% purity. The system exhibited resilience against typical industrial impurities, maintaining high performance. These results mark a crucial advancement in scaling tandem CO2 electrolysis systems toward industrial feasibility. Finally, an experimentally informed techno-economic analysis is offered to provide a pathway for commercially viable tandem CO2 electrolysis at an industrial scale. Tandem CO2 electrolysis has demonstrated strong potential for transforming captured CO2 into multicarbon products, but more effort is needed in scaling these systems to commercial levels. The authors address this crucial need by elevating tandem CO2 electrolysis to the kilowatt scale, marking a significant step toward real-world implementation.