Conversion of CO2 to Hydrocarbons in Gasoline, Jet, and Diesel Fuel C n -Range via Electrochemical CO2 Reduction and Organometallic Ethylene-CO Copolymerization and Ethylene Oligomerization

Abstract Conversion of CO2 into fuels is a potential method to diversify carbon feedstocks and utilize a greenhouse gas. Electrochemical CO2 reduction (eCO2R) is a pathway to convert CO2 into ethylene and CO at mild conditions using renewable electricity. Fuel-grade hydrocarbons can be produced by ethylene oligomerization; however, CO often poisons ethylene oligomerization catalysts, requiring expensive CO removal processes. To integrate the impure intermediate feedstock of CO and ethylene derived from CO2 and the molecular catalysts required for Cn product generation without substantial CO poisoning, optimization of both electrochemical and organometallic catalysis was required. Herein, we demonstrate C4–C28 hydrocarbon production from CO2 and water with CO capture via ethylene-CO copolymerization instead of ethylene purification. For this system, we developed Pd-phosphinosulfonate-borane adduct catalysts that tolerate small quantities of CO while retaining ethylene oligomerization activity, forming internal olefins. The eCO2R performance was optimized to increase the ethylene-to-CO ratio as necessary for efficient conversion to fuels, reaching over 18% ethylene with a 2.4-fold excess over CO under recirculation. Ethylene oligomer formation is achieved with a Faradaic efficiency (FE) of 17% and a CO2 conversion (χCO2) of 5%, while the FE and χCO2 toward polymers are 18% and 7%.