Electrochemical reduction of carbon dioxide on copper-based cathodes in electrochemical tubular fixed bed reactor

Abstract

CO2 electrochemical reduction reaction (CO2ERR) has been investigated with an aim to eventually become a means to decrease the concentration of CO2 in the atmosphere to hydrocarbons by proton and electron transfer. The product distribution strongly depends on cathode materials. Copper is a unique metal in its ability to catalyze the electrochemical reduction of CO2 to various hydrocarbons including ethylene, but the main problems are the poor solubility CO2 in aqueous solutions. In this study, the performance of CO2ERR is improved by increasing pressure. The ionomer copper foam is used as a cathode in the electrochemical tubular fixed bed reactor for continuous conversion of CO2 to ethylene to observe the selectivity of CO2 pressure. The result show faradic efficiency (FE) of ethylene on 10 bar is 2 and 6 times higher than 5 and 3 bar, respectively and FE of CO is decreased for C-C coupling to ethylene production. Moreover, The effect of cell voltages are studied by potentialstat controlling. the results show FE of ethylene and CO are decreased because protons reduce intermediated CO on the cathode surface and lead to suppress CO2 reduction while cell voltage and current are increased.