Molybdenum-induced interfacial electron pump stabilizes γ-NiOOH for efficient electrooxidation conversion of methanol into formate

A two-step strategy of electrosynthesis-solvothermal process builds NiMo/G composites with Ni-O-Mo bridges. • Mo acts as interfacial electron pump, locking Ni in high-valent state. • Electron modulation lowers γ-NiOOH formation barrier by ∼150 mV and CH 3 O →  CH 2 O step to 0.46 eV. • NiMo/G delivers 320.6 ± 5.2 mA cm −2 and 15,638.9 ± 254.1 mA mg Ni −1 , enabling low-overpotential formate pathway. The intrinsic instability of the active γ-NiOOH phase severely limits the performance of nickel-based electrocatalysts for the methanol oxidation reaction (MOR). Herein, we report a Mo-induced interfacial electron pump strategy to stabilize the γ-NiOOH lattice and boost MOR efficiency. Via a distinctive two-step strategy of electrolysis and subsequent solvothermal reaction, we construct NiMo/graphene (NiMo/G) composites rich in Ni-O-Mo interfaces, where Mo centers continuously withdraw electrons from adjacent Ni sites, functioning as efficient electron sinks. This precise electronic modulation lowers the thermodynamic barrier for γ-NiOOH formation by ∼150 mV and optimizes the adsorption energetics for intermediates, reducing the energy barrier of the rate-determining *CH 3 O → *CH 2 O step from 0.68 to 0.46 eV, thereby directing the reaction along a low-overpotential formate pathway. Consequently, this optimized NiMo/G catalyst achieves exceptional area activity of 320.6 ± 5.2 mA cm −2 and mass activity of 15,638.9 ± 254.1 mA mg Ni −1 , respectively. This work establishes interfacial electron pump engineering as a general and powerful strategy for stabilizing high-valent active phases in advanced energy conversion and storage technologies. Download: Download high-res image (183KB) Download: Download full-size image