Establishing Non‐stoichiometric Ti4O7 Assisted Asymmetrical C‐C Coupling for Highly Energy‐Efficient Electroreduction of Carbon Monoxide

Exploring an appropriate support material for Cu‐based electrocatalyst is conducive for stably producing multi‐carbon chemicals from electroreduction of carbon monoxide. However, the insufficient metal‐support adaptability and low conductivity of the support would hinder the C‐C coupling capacity and energy efficiency. Herein, non‐stoichiometric Ti4O7 was incorporated into Cu electrocatalysts (Cu‐Ti4O7), and served as a highly conductive and stable support for highly energy‐efficient electrochemical conversion of CO. The abundant oxygen vacancies originated from ordered lattice defects in Ti4O7 facilitate the water dissociation and the CO adsorption to accelerate the hydrogenation to *COH. The highly adaptable metal‐support interface of Cu‐Ti4O7 enables a direct asymmetrical C‐C coupling between *CO on Cu and *COH on Ti4O7, which significantly lowers the reaction energy barrier for C2+ products formation. Additionally, the excellent electroconductivity of Ti4O7 benefits the reaction charge transfer through robust Cu/Ti4O7 interface for minimizing the energy loss. Thus, the optimized 20Cu‐Ti4O7 catalyst exhibits an impressive selectivity of 96.4% and ultrahigh energy efficiency of 45.1% for multi‐carbon products, along with a remarkable partial current density of 432.6 mA cm‐2. Our study underscores a novel C‐C coupling strategy between Cu and the support material, advancing the development of Cu‐supported catalysts for highly efficient electroreduction of carbon monoxide.