Improving CO-to-C Product Electroreduction Efficiency Atomic Lanthanide Dopant-Induced Tensile-Strained CuO Catalysts

Cu is a promising electrocatalyst in CO reduction reaction (CORR) to high-value C products. However, as important C-C coupling active sites, the Cu species is usually unstable under reduction conditions. How atomic dopants affect the performance of Cu-based catalysts is interesting to be studied. Herein, we first calculated the difference between the thermodynamic limiting potentials of CORR and the hydrogen evolution reaction, as well as the *CO binding energy over CuO doped with different metals, and the results indicated that doping atomic Gd into CuO could improve the performance of the catalyst effectively. On the basis of the theoretical study, we designed Gd/CuO catalysts. The distinctive electronic structure and large ion radii of Gd not only keep the Cu species stable during the reaction but also induce tensile strain in Gd/CuO, resulting in excellent performance of the catalysts for electroreduction of CO to C products. The Faradic efficiency of C products could reach 81.4% with a C product partial current density of 444.3 mA cm at -0.8 V vs a reversible hydrogen electrode. Detailed experimental and theoretical studies revealed that Gd doping enhanced CO activation on the catalyst, stabilized the key intermediate O*CCO, and reduced the energy barrier of the C-C coupling reaction.