Facet-Dependent Selectivity of Cu Catalysts in Electrochemical CO(2) Reduction at Commercially Viable Current Densities

[Image: see text] Despite substantial progress in the electrochemical conversion of CO(2) into value-added chemicals, the translation of fundamental studies into commercially relevant conditions requires additional efforts. Here, we study the catalytic properties of tailored Cu nanocatalysts under commercially relevant current densities in a gas-fed flow cell. We demonstrate that their facet-dependent selectivity is retained in this device configuration with the advantage of further suppressing hydrogen production and increasing the faradaic efficiencies toward the CO(2) reduction products compared to a conventional H-cell. The combined catalyst and system effects result in state-of-the art product selectivity at high current densities (in the range 100–300 mA/cm(2)) and at relatively low applied potential (as low as −0.65 V vs RHE). Cu cubes reach an ethylene selectivity of up to 57% with a corresponding mass activity of 700 mA/mg, and Cu octahedra reach a methane selectivity of up to 51% with a corresponding mass activity of 1.45 A/mg in 1 M KOH.