Plastic from CO2, Water, and Electricity: Tandem Electrochemical CO2 Reduction and Thermochemical Ethylene‐CO Copolymerization

Converting CO2 into industrially useful products is an appealing strategy for utilization of an abundant chemical resource and for sequestration of a greenhouse gas. Electrochemical CO2 reduction (eCO2R) offers a pathway to convert CO2 into CO and ethylene, using renewable electricity. These products can be efficiently copolymerized by organometallic catalysts to generate polyketones. However, the conditions for these reactions are very different, presenting the challenge of coupling microenvironments typically encountered for the transformation of CO2 into highly complex but desirable multicarbon products. Herein, we present a system to produce polyketone plastics entirely derived from CO2 and water, where both the CO and C2H4 intermediates are produced by eCO2R. In this system, a combination of Cu and Ag gas diffusion electrodes is used to generate a gas mixture with nearly equal concentrations of CO and C2H4, and a recirculatory CO2reduction loop is used to reach concentrations of above 11% each, leading to a current‐to‐polymer efficiency of up to 51% and CO2 utilization of 14%.