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.