Engineering of the d‐Band Center of Perovskite Cobaltite for Enhanced Electrocatalytic Oxygen Evolution

Great efforts have been made to understand and upgrade the kinetically sluggish oxygen evolution reaction (OER). In this study, a series of V-doped LaCoO3 (V-LCO) OER electrocatalysts with optimized d-band centers are fabricated. When utilized as an electrode for the OER, as-formed LaCo0.8 V0.2 O3 (V-LCO-II) requires an overpotential of only 306 mV to drive a geometrical catalytic current density of 10 mA cm-2 . Furthermore, at a given overpotential of 350 mV, the OER current density of V-LCO-II is about 22 times that of pure LaCoO3 (LCO) nanoparticles. Tailoring of the d-band center by V doping facilitates the adsorption of OER intermediates and promotes the formation of amorphous active species on the surface of LCO through the exchange interaction between high-spin V4+ and low-spin Co2+ . This work may create new opportunities for developing other highly active OER catalysts through d-band center engineering.