Metallic–Dissolution Triggered Defective NiCoAl‐CuO Electrocatalyst for Enhanced Ethanol Oxidation Reaction With Precisely Tuned Reaction Pathway

ABSTRACT Replacing the sluggish anodic oxygen evolution reaction (OER) with value‐added processes like the ethanol oxidation reaction (EOR) enhances the economic viability of water electrolysis. However, the rational design of low‐cost, durable electrocatalysts that selectively drive partial oxidation pathways under harsh anodic conditions remains a significant challenge. Here, we report a selective metallic‐dissolution strategy to create a defect‐rich NiCoAl‐hydroxide catalyst on a CuO nanowire scaffold. Controlled electrochemical Al leaching reconstructs the catalyst surface and creates defective Al and O sites that optimize the binding energies for C2 ethanol oxidation pathway intermediates, thereby substantially lowering the activation barrier of the rate‐determining step. The final catalyst achieves a remarkable 278 mV potential reduction for EOR compared to OER and maintains exceptional stability for over 45 h. When integrated into a hybrid electrolysis system, it enables the co‐production of H 2 and acetate with Faradaic efficiencies of 98.5% and 91.2%, respectively, at a substantially lower cell voltage, presenting a novel pre‐activation approach for designing advanced electrocatalysts.