Electrocatalytic Ethanol-to-Acetate Conversion With Nearly 100% Faradaic Efficiency Enabled by Cu-Doping Strategy for Enhancing Selective and Cooperative Adsorption.

Electrocatalytic biomass-based ethanol coupled with water electrolysis for hydrogen production can significantly reduce hydrogen production energy consumption while generating high-valued acetate. However, nickel-based non-precious metal electrocatalysts exhibit low selectivity and stability due to imbalanced adsorption of ethanol reactants and OH-. Herein, Cu-doped Ni(OH)2 nanosheets were prepared for the selective electrooxidation of ethanol to acetate, achieving nearly 100% Faradaic efficiency (FE) and 108 h stability. In situ electrochemical testing and theoretical calculations indicated that Cu doping promoted the cooperative of OH- at Cu sites, thereby effectively switching the rate-determining step from *CH3CHO dehydrogenation to *CH3CO─OH- coupling. This synergistically adsorption mechanism reduces the thermodynamic barrier to 1.56 eV. Additionally, the constructed dual-electrode system delivered a current density of 50 mA cm-2 at a cell voltage of 1.54 V, along with over 55 h stability and high FEs. This work demonstrates the importance of cooperative adsorption behavior of ethanol and OH- in the ethanol oxidation process, which is beneficial to enhancing the production efficiency of green hydrogen and acetate through electrochemical methods.