Ampere‐Level Hydrogen Generation via 1000 H Stable Seawater Electrolysis Catalyzed by Pt‐Cluster‐Loaded NiFeCo Phosphide

Abstract Seawater electrolysis can generate carbon‐neutral hydrogen but its efficiency is hindered by the low mass activity and poor stability of commercial catalysts at industrial current densities. Herein, Pt nanoclusters are loaded on nickel‐iron‐cobalt phosphide nanosheets, with the obtained Pt@NiFeCo‐P electrocatalyst exhibiting excellent hydrogen evolution reaction (HER) activity and stability in alkaline seawater at ampere‐level current densities. The catalyst delivers an ultralow HER overpotential of 19.7 mV at −10 mA cm −2 in seawater‐simulating alkaline solutions, along with a Pt‐mass activity 20.8 times higher than Pt/C under the same conditions, while dropping to 8.3 mV upon a five‐fold NaCl concentrated natural seawater. Remarkably, Pt@NiFeCo‐P offers stable operation for over 1000 h at 1 A cm −2 in an alkaline brine electrolyte, demonstrating its potential for efficient and long‐term seawater electrolysis. X‐ray photoelectron spectroscopy (XPS), in situ electrochemical impedance spectroscopy (EIS), and in situ Raman studies revealed fast electron and charge transfer from the NiFeCo‐P substrate to Pt nanoclusters enabled by a strong metal‐support interaction, which increased the coverage of H * and accelerated water dissociation on high valent Co sites. This study represents a significant advancement in the development of efficient and stable electrocatalysts with high mass activity for sustainable hydrogen generation from seawater.