Chlorine-promoted copper catalysts for CO2 electroreduction into highly reduced products

Chlorinated copper catalysts have shown promise for electroreduction of carbon dioxide to complex products, but the challenging control chlorination keeps shaded potential chlorine as a selectivity promoter. This work develops gas-phase strategy based on exposure diluted hydrochloric acid at different temperatures study effect content in (II) oxide (CuO), (I) (Cu2O), and metallic (Cu) foils. Contrary CuO Cu, Cu2O enhances formation highly reduced products (those requiring more than two electron transfers). Faradaic efficiency toward these (0%–14% -0.8 V vs. reversible hydrogen electrode) correlates with surface after reaction (0 1.8 atom % chlorine), which is maximized mild initial degrees (Cu2O:CuCl∼1). Experimental computational studies suggest surfaces moderate coverage oxychloride-like clusters are active sites responsible promotional effect. These findings may facilitate structure-performance relationships, forwarding next generation this family catalysts.