Membrane-electrode assembly electrolysis of CO2 to formate using indium nitride nanomaterials

A new mode of membrane-electrode assembly based electrolysis was adopted for efficient electrochemical reduction of carbon dioxide (CO2RR) to formate. InN-C nanomaterials were employed as the CO2RR electrocatalyst, which showed excellent catalytic activity and high selectivity to produce formate, because of nitridation to form more basic sites. In aqueous phase, the maximum Faradaic efficiency (FE) by InN-C for formate was 92.2 % at -0.9 V vs RHE, higher than that of In2O3-C catalyst. In MEA electrolysis, the maximum FE reached 92.5 % at the cell voltage of 2.96 V with formate partial current density of 60.1 mA cm−2. The increased reactivity was due to optimized gas-liquid biphase transport of CO2, which is quite limited in single aqueous phase.