Abstract

Abstract Regulating the binding effect between the surface of an electrode material and reaction intermediates is essential in highly efficient CO 2 electro‐reduction to produce high‐value multicarbon (C 2+ ) compounds. Theoretical study reveals that lattice tensile strain in single‐component Cu catalysts can reduce the dipole–dipole repulsion between *CO intermediates and promotes *OH adsorption, and the high *CO and *OH coverage decreases the energy barrier for C−C coupling. In this work, Cu catalysts with varying lattice tensile strain were fabricated by electro‐reducing CuO precursors with different crystallinity, without adding any extra components. The as‐prepared single‐component Cu catalysts were used for CO 2 electro‐reduction, and it is discovered that the lattice tensile strain in Cu could enhance the Faradaic efficiency (FE) of C 2+ products effectively. Especially, the as‐prepared Cu TPA catalyst with high lattice tensile strain achieves a FE C2+ of 90.9 % at −1.25 V vs. RHE with a partial current density of 486.1 mA cm −2 .