Selective Ethylene Production from CO 2 and CO Reduction via Engineering Membrane Electrode Assembly with Porous Dendritic Copper Oxide.

Gas-fed zero-gap electrolyzers have recently emerged as attractive systems for limiting ohmic losses and costs associated with electrolytes and for optimizing energy efficiencies. Here, we report that using a dendritic Cu oxide (D-CuO) material deposited on a gas diffusion layer as the cathode of a gas-fed zero-gap membrane electrode assembly (MEA) system results in a very selective conversion of CO to ethylene. More specifically, CO reduction yielded ethylene with an FE up to 68% at 100-125 mA·cm -2 with H 2 as the only other gaseous product and the electrolysis could be carried out for several hours with good stability. Ethylene was also the major product during CO 2 electrolysis (FE = 41%) at 125-150 mA·cm -2 , reflecting the high selectivity of D-CuO for ethylene production. Such systems are relevant for tandem CO 2 electroreduction processes, allowing energy efficiencies above 30%.