Utilizing reconstruction achieves ultrastable water electrolysis

The dissolution of active atoms under operating potential will lead to a decline in their oxygen evolution reaction (OER) performance, thus preventing the current highly active catalysts from being practically applicable in industrial water electrolysis. Here, we propose a sequential leaching strategy to utilize the dynamic restructuring and enhance the chemical bond strength for highly active and stable OER. Modeling on nickel-iron sulfides (NiFe-S), we introduced and utilized foreign Mo dopant preleaching as the sacrificial agent to alleviate the oxidation corrosion of partial M─S bonds. Operando spectroscopic reveal that foreign Mo dopant leach from the matrix and then adsorb on the surface of NiFe O(S)OH as molybdate at lower OER potential. The crystal occupation hamiltonian population analysis uncovers that the charge transfer from molybdate into NiFe O(S)OH will enhance bond energy of M─S, thus preventing further S and Fe/Ni leaching. By manipulating ion leaching, the resulting active phase achieves an ultralow overpotential of 250 mV at 400 mA cm^-2 and high stability of more than 3,700 h at 100 mA cm^-2. An industrial water electrolysis equipment using our catalysts delivered ultralow energy consumption of 4.30 kWh m^-3_H2 and record stability over 250 h (2,300 h lifetime by epitaxial method with 10% attenuation) under a high working current of 8,000 mA. The hydrogen production cost of US$2.46/kg_H2 aligns with the green hydrogen cost target set by the European Commission for the coming decade.