Enhanced electrocatalytic methanol oxidation to formate on iron-substituted nickel oxide

Electrochemical methanol oxidation reaction (MOR) provides a promising route to reduce the anodic overpotential of water electrolysis while co-generating value-added chemicals. However, developing cost-effective catalysts that achieve highly efficient and selective methanol-to-formate conversion remains a significant challenge. In this work, we developed a series of potential cost-effective electrocatalysts synthesized via a hydrothermal-calcination route. Among them, the iron-substituted nickel oxide (Fe-NiO) electrode delivers the highest current density of ∼150 mA cm^-2 at 1.60 V vs. RHE, and remarkable MOR selectivity with a formate Faradaic efficiency of ∼100%, largely above control samplesof pristine NiO-, and Fe₂O₃-based electrode. At a lower external potential of 1.55 V, this electrode presents a remarkable stability, sustaining a high current density over 100 mA cm^-2 even at the end of 100 h operation.Advanced characterization combined with density functional theory (DFT) calculations reveals that Fe incorporation modulates the electronic structure of NiO, optimizes the adsorption of key reaction intermediates, and significantly reduces the energy barrier of the rate-determining step. This work establish an effective electronic-structure engineering strategy for designing earth-abundant, high-performance MOR electrocatalysts and provides mechanistic insights into tuning metal oxides for energy-efficient hydrogen co-production.