Unraveling Lattice Dislocation‐Driven Energy Band Convergence Mechanism to Enhance Electrocatalytic Hydrogen Production in Alkaline Seawater

Abstract Hydrogen evolution reaction (HER) from seawater electrolysis still faces challenges of low reactivity and chloride ions poison at the active sites, leading to reduced efficiency and stability of electrocatalysts. This study presents edge dislocation strategy aimed at inducing lattice strain in ferric oxide through Mo doping, consequently regulating the catalyst's band structure. Through in situ characterizations and DFT analysis, it is confirmed that lattice strain effectively modulates the band structure, intensifies the hybridization between Mo(d)‐Fe(d)‐O(p) orbitals, thereby accelerating the charge transfer rate of HER. Furthermore, band structure modulated by lattice strain enhances water adsorption capacity, reduces the adsorption energy of Cl⁻, and optimizes the hydrogen adsorption‐free energy (ΔG_H*) for HER. Benefiting from above, the optimized 2%‐Mo‐Fe₂O₃ catalyst demonstrates HER activity and stability in alkaline seawater electrolysis comparable to that of commercial Pt/C. Additionally, the assembled electrolytic cell utilizing an anion exchange membrane (AEM) maintains long‐term stability for >100 h at 500 mA cm⁻², showcasing a sustained catalytic effect.