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 US2. 46/kg H2 aligns with the green hydrogen cost target set by the European Commission for the coming decade.