Selective CO(2) Electroreduction to Ethylene and Multicarbon Alcohols via Electrolyte‐Driven Nanostructuring

Production of multicarbon products (C(2+)) from CO(2) electroreduction reaction (CO(2)RR) is highly desirable for storing renewable energy and reducing carbon emission. The electrochemical synthesis of CO(2)RR catalysts that are highly selective for C(2+) products via electrolyte‐driven nanostructuring is presented. Nanostructured Cu catalysts synthesized in the presence of specific anions selectively convert CO(2) into ethylene and multicarbon alcohols in aqueous 0.1 m KHCO(3) solution, with the iodine‐modified catalyst displaying the highest Faradaic efficiency of 80 % and a partial geometric current density of ca. 31.2 mA cm(−2) for C(2+) products at −0.9 V vs. RHE. Operando X‐ray absorption spectroscopy and quasi in situ X‐ray photoelectron spectroscopy measurements revealed that the high C(2+) selectivity of these nanostructured Cu catalysts can be attributed to the highly roughened surface morphology induced by the synthesis, presence of subsurface oxygen and Cu(+) species, and the adsorbed halides.