Transition Metal Phosphides for Seawater Electrolysis: Dynamic Reconstruction, Synergistic Mechanisms and Design Paradigms

ABSTRACT Amid the accelerated expansion of the green hydrogen industry, seawater electrolysis is emerging as a pivotal route for large‐scale hydrogen production, owing to its abundant feedstock and cost advantages. Nevertheless, the competing anode corrosion reaction and the intrinsically sluggish OER kinetics engendered by high chloride concentrations impose decisive constraints on the industrial deployment of conventional catalysts. Transition Metal Phosphides (TMPs), characterized by metallic conductivity, tunable electronic structures, and high intrinsic activity, have become the catalytic system of choice for overcoming these limitations. Under electrochemical conditions, TMP surfaces undergo dynamic reconstruction to enhance performance through a synergistic mechanism: electron redistribution effect, lattice oxygen activation, and an in situ corrosion barrier that electrostatically repels Cl − . To bridge the gap between laboratory validation and industrial realization, this review systematically explores optimization strategies encompassing compositional design, structural innovation, and dynamic interface regulation. In real seawater and at industrially relevant current densities exceeding 500 mA cm − 2 , TMP electrodes demonstrate substantial potential; nonetheless, large‐scale deployment still confronts formidable challenges. Future efforts must integrate operando XAFS/Raman characterization with Machine Learning driven data analytics to unravel atomic‐scale reconstruction pathways and resolve engineering hurdles associated with high current density, prolonged durability, and complex environmental adaptability, thereby propelling TMP‐based seawater electrolysis toward practical implementation in gigawatt‐level green hydrogen plants.