Steering benzyl alcohol electrooxidation coupled with hydrogen evolution via hetero-interface construction

It is still a challenge to develop electrocatalyst for the efficient adsorption and conversion of organic molecule in aqueous media. Herein, a hetero-interface structure based on CuO@Ni(OH)2 is rationally designed to enhance the performance of benzyl alcohol oxidation to benzoic acid. A high Faradaic efficiency of 99% and the yield of 3.09 mmol cm-2 h-1 are achieved at 1.70 V versus reversible hydrogen electrode, outperforming the previously reported electrocatalysts. Furthermore, a membrane-free flow electrolyzer was assembled based on CuO@Ni(OH)2 hetero-interface, exhibiting a much high yielding of benzoic acid (6.73 mmol cm-2 h-1) and hydrogen (0.35 L cm-2 h-1) with excellent stability. Both experimental data and density functional theory calculations verify that the electron is tend to accumulate at the hetero-interface, thus accelerating the adsorption of reactant and intermediate and reducing the energy barrier of the conversion of benzyl alcohol to benzoic acid.