Vanadate-Mediated\nMismatch Configuration over the\nReconstructed Nickel–Iron Electrocatalyst for Boosting Alkaline\nOxygen Evolution

During the oxygen evolution reaction (OER), catalyst\ncandidates\nthat can fully trigger self-reconstruction to derive active species\nwith favorable configurations are expected to overcome the sluggish\nreaction kinetics. Herein, we innovatively propose the introduction\nof heterogeneous vanadate dopants into nickel–iron alloy precatalysts,\nwhere the crystal mismatch structure induces local electron delocalization\nin the hexagonal close packed alloy phase, thereby facilitating adequate\nelectrochemical reconstruction to form (oxy)hydroxides as the real\ncatalytic species. Simultaneously, the participation of vanadate in\nthe reconstruction also triggers mismatch in the derived (oxy)hydroxides,\nreinforcing the metal–oxygen covalence, so that lattice oxygen\nactivation is kinetically favorable and facilitates the OER via the\nlattice oxygen pathway. Optimized reconstructed catalyst r-NiFeVO<sub><i>x</i></sub>-NF exhibits a low overpotential of 220 mV\nat current densities of 10 mA cm<sup>–2</sup> and considerably\nstable operation. Our study opens up opportunities for achieving robust\nOER performance through the design and fabrication of the mismatch\ncatalytic configuration.