Cu/Mn-modulated self-supported Ni catalyst with a hierarchical architecture for efficient ethanol oxidation-coupled hydrogen production.

Replacing the oxygen evolution reaction with the ethanol oxidation reaction offers a promising route to reduce the energy demand of hydrogen production while co-generating value-added chemicals. Herein, we report a self-supported Cu/Mn-modulated Ni electrode prepared by high-current-density electrodeposition as an efficient non-precious-metal catalyst for ethanol oxidation-coupled hydrogen production. Benefiting from the hierarchical nanostructure formed during hydrogen-evolution-assisted deposition and the electronic modulation of the Ni framework by Cu and Mn, the electrode exhibits a low potential at 10 mA cm-2 of 1.294 V versus RHE, a faradaic efficiency of 93.49% for acetate formation, and long-term stability over 400 h. When integrated into a silicon photovoltaic-electrochemical system, it delivers a solar-to-chemical efficiency of 0.55% and a hydrogen production rate of 1.1 mmol cm-2 h-1 with negligible oxygen evolution. These results highlight the potential of low-cost Ni-based electrodes for coupling selective alcohol oxidation with renewable hydrogen production.