Copper Nanowires for Electrochemical CO2 Reduction Reaction

Abstract

A promising carbon capture and utilization strategy is the electrochemical reduction of CO2 (eCO2R) to value-added chemicals. Critical to the success of this approach is the development of catalysts capable of selectively converting aqueous CO2 into a specific product. Copper (Cu) is considered the best pure metal candidate for eCO2R for its ability to catalyze the formation of several hydrocarbons, aldehydes, and alcohols. However, Cu lacks the required selectivity. In this regard, a fine-tuned control of its surface topology and nanostructuring could allow the enhancement of eCO2R catalysis. Here, we report a computational investigation of the growth tendency of Cu nanowires (NWs) as well as their ability to adsorb, activate, and convert CO2 to one- and two-carbon products to understand their potential application as eCO2R catalysts. Grand canonical Monte Carlo simulations of the growth of Cu nanowires with diameters between 0.8 to 2 nm showed the tendency to form regular nanowires with a facet center cubic unit cell pattern. Cu nanowires demonstrated a pronounced propensity to activate CO2, particularly those with a 0.8 nm diameter, owing to the markedly uncoordinated Cu atoms on the surface and higher d-band center, which effectively promotes CO2 interaction with the surface, molecule bending, C-O bond elongation, and charge transfer from the catalyst to CO2. Calculation of the CO2 conversion to C1 products shows the Cu NWs to be highly selective to carbon monoxide, a key intermediate ion in the generation of C2 products.