The Corrosive Cl<sup>–</sup>‑Induced\nRapid Surface Reconstruction of Amorphous NiFeCoP Enables Efficient\nSeawater Splitting

Limited by the violent oxidation and corrosion environment\nof the\noxygen evolution reaction (OER) in seawater electrolysis, the design\nof catalysts with high activity and stability is crucial for improving\nthe hydrogen production performance of the electrolysis cell. Herein,\nwe report taking advantage of corrosive Cl<sup>–</sup> in seawater\nto achieve rapid surface reconstruction of amorphous NiFeCoP for stable\nseawater splitting. The successful introduction of pulse current and\nP constructs Cl<sup>–</sup> adsorption active sites to optimize\nthe d-band center and induce the formation of NiFeCo(OH). Density\nfunctional theory calculations also verified that NiFeCo(OH) has satisfactory\nOER activity and chlorine exclusion properties. Benefiting from the\nelectronic structure and reaction intermediate adsorption, NiFeCo(OH)\nonly requires 255.3 mV overpotential to reach a current density of\n100 mA cm<sup>–2</sup>. Meanwhile, the assigned alkaline water\nelectrolysis cell (NFCP || Pt/C) stably operates for 320 h in natural\nseawater at an industrial current density of 500 mA·cm<sup>–2</sup> with a low voltage of 1.806 V. The seawater AEM electrolyzer (NFCP\n|| Pt/C) achieves an improved performance of high activity (2.095\nV@500 mA·cm<sup>–2</sup>) and stable operation (100 h@500\nmA·cm<sup>–2</sup>) to achieve economic seawater splitting.\nIn summary, this work proposes a fast self-reconstruction of a high-performance\nseawater electrocatalyst for marine hydrogen energy.