Zero-crossover electrochemical CO2 reduction to ethylene with co-production of valuable chemicals

To date, electrochemical reduction of CO2 (eCO(2)R) is plagued by undesirable carbonate formation and crossover that adds an energy penalty. Using a bipolar membrane, copper cathode, and gold nano-dendrite ( Au-ND) anode, we report eCO(2)R to C2H4 on cathode coupledwith glycerol oxidation on anode with zero carbonate crossover. The co-electrolysis system operated at high current densities of 175-225 mA/cm(2) and C2H4 faradaic efficiency (FE) of 50%. The full cell voltages were between 3.9 and 4.4 V, which represented a decrease of 0.8 V versus conventional eCO2R. In addition, the AuND catalyst demonstrated high FE of 50% for glycolic acid (GA) production, which helped drive economic feasibility of the process. Our techno-economic analysis indicated that, while it would be improbable to commercialize a conventional eCO(2)R-to- C2H4 process, a coelectrolysis process to produce C2H4 from CO2 and GA from crude glycerol, with zero carbonate crossover, can attain a competitive minimum selling price (MSP) of C2H4 similar to$1.1/kgC(2)H(4).

Automated summary

We have developed a co-electrolysis process that efficiently converts CO2 to ethylene (C2H4) while simultaneously oxidizing glycerol on the anode, eliminating unwanted carbonate formation and crossover. The process operates at high current densities and exhibits promising faradaic efficiency and economic feasibility.