The Corrosive Cl–-Induced Rapid Surface Reconstruction of Amorphous NiFeCoP Enables Efficient Seawater Splitting

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