Electrochemical reduction of CO2 with clathrate hydrate electrolytes and copper foam electrodes

•CO2 containing clathrate hydrates were used as an electrolyte additive in the electrochemical reduction of CO2•Concentration of CO2 in solution was significantly increased without pressurization•Results with clathrates show 80% Faradaic efficiency for CO and further reduced carbonaceous products at − 1.0 V vs Ag/AgCl•Clathrate hydrates may offer a method to both capture and convert CO2

We report on the first use of clathrate hydrates as electrolyte additive in the electrochemical reduction of carbon dioxide. Clathrate hydrates allow the enrichment of significantly larger volumes of gas than liquids can usually dissolve. Electrolyte solutions containing 10%mass THF with and without CO2 containing clathrate hydrates were investigated with a copper-foam working electrode. Our results show that at − 1.0 V vs Ag/AgCl the Faradaic efficiency for the production of CO and further reduced carbonaceous products was 80% with clathrates vs 20% with non-clathrate electrolytes of identical chemical composition at nearly equal temperature.