Synergistic Effect of Cu₂ O Mesh Pattern on High-Facet Cu Surface for Selective CO₂ Electroreduction to Ethanol.

Abstract

Although the electroconversion of carbon dioxide (CO₂ ) into ethanol is considered to be one of the most promising ways of using CO₂ , the ethanol selectivity is less than 50% because of difficulties in designing an optimal catalyst that arise from the complicated pathways for the electroreduction of CO₂ to ethanol. Several approaches including the fabrication of oxide-derived structures, atomic surface control, and the Cu⁺ /Cu interfaces have been primarily used to produce ethanol from CO₂ . Here, a combined structure with Cu⁺ and high-facets as electrocatalysts is constructed by creating high-facets of wrinkled Cu surrounded by Cu₂ O mesh patterns. Using chemical vapor deposition graphene growth procedures, the insufficiently grown graphene is used as an oxidation-masking material, and the high-facet wrinkled Cu is simultaneously generated during the graphene growth synthesis. The resulting electrocatalyst shows an ethanol selectivity of 43% at -0.8 V versus reversible hydrogen electrode, which is one of the highest ethanol selectivity values reported thus far. This is attributed to the role of Cu⁺ in enhancing CO binding strength, and the high-facets, which favor C-C coupling and the ethanol pathway. This method for generating the combined structure can be widely applicable not only for electrochemical catalysts but also in various fields.