Efficient electrochemical CO2 reduction to C2+ hydrocarbons on Zn-doped Cu films

In the context of the electrochemical CO2 reduction reaction (CO2RR) aimed at producing economically viable multi-carbon (C2+) hydrocarbons, copper (Cu)-based catalysts face the formidable challenge of surmounting the substantial energy barrier inherent in the C–C coupling reaction of the adsorbed *CO intermediate, while simultaneously contending with the hydrogen evolution reaction. To address these complexities, we employed magnetron co-sputtering to introduce zinc (Zn), acknowledged as a catalyst for CO formation, into the Cu matrix. This process serves to elevate the concentration of the pivotal intermediate *CO, thus augmenting the efficiency of the C–C coupling reaction. The doping of a minute quantity of Zn induces modifications in the electronic structure, consequently leading to a downward shift of the d-band center. This alteration significantly reduces the adsorption energy of *CO on the CuZn surface. As a consequence, we observed that the Faraday efficiency (FE) for C2+ products achieved an impressive 80 % with a current density of −120 mA/cm2 at −1.17 V versus a reversible hydrogen electrode when employing the CuZn catalyst. Our research establishes a meticulous and efficient avenue for precisely controlling atomic ratios, thereby facilitating the promotion of a highly active electrochemical CO2 reduction toward C2+ hydrocarbons.