Highly efficient electrocatalytic CO2-to-ethanol conversion over bimetallic CuPd catalysts via selective CC coupling.

Modification of copper-based catalysts by heteroatom doping is an effective method to improve the electrocatalytic reduction of carbon dioxide to C2+. However, electrocatalytic reduction of carbon dioxide to ethanol has the problem of low selectivity and low Faradaic efficiency. Herein, bimetallic catalyst CuPdx was prepared by a simple one-pot method. The CuPd0.1 achieves a high C2+ Faradaic efficiency of 72.5%, in particular its electrocatalytic reduction of carbon dioxide to ethanol with a Faradaic efficiency of up to 63.0% in flow-cell. Besides, the partial current density of ethanol of CuPd0.1 can reach up to 335 mA·cm-2 at 1.16 V (vs. RHE). Experiments and theories calculation revealed that the incorporation of Pd into Cu nanoparticles (NPs) triggers structural reconstruction, optimizing the distribution and exposure of active sites while introducing additional oxygen vacancies, which significantly enhances CO2 adsorption. Furthermore, Pd doping regulates the adsorption energy barrier of H* and significantly reduces the energy barrier for CC coupling, steering the reaction pathway toward ethanol production. This synergistic effect substantially improves the selectivity for ethanol formation. Therefore, appropriate amount of Pd doping can improve the selectivity and catalytic activity of Cu NPs in electrocatalytic reduction of carbon dioxide to produce ethanol.