Selective electrochemical reduction of carbon dioxide to ethanol by relay catalytic platform

Efficient electroreduction of carbon dioxide (CO2) to ethanol is of great importance, but this remains a challenge because it involves transfer of multiple proton-electrons and carbon-carbon coupling. Herein, we report a CoO-anchored N-doped carbon material composed of mesoporous carbon (MC) and carbon nanotube (CNT) as a catalyst for CO2 electroreduction. The faradaic efficiency of ethanol and current density reached 60.1% and 5.1 mA cm−2 respectively. Moreover, the selectivity of ethanol products was extremely high among the products produced from CO2. A proposed mechanism was discussed that the MC-CNT/Co catalyst provided a relay catalytic platform, where CoO catalyze the formation of CO* intermediates which spill over to MC-CNT for carbon-carbon coupling to form ethanol. The high selectivity of ethanol was attributed mainly to the highly selective carbon-carbon coupling active site on MC-CNT.