The synergistic effect of Ir and oxygen vacancies on Enhancing the OER performance of Surface-Reconstructed FeCo LDH

The modification of Ir or oxygen vacancies (V o ) is a strategy to enhance the oxygen evolution reaction (OER) performance of heterogeneous nanocatalysts. However, it is crucial to further clarify the synergistic effect of Ir and V o on the enhancement mechanism of OER performance after surface reconstruction. In this work, FeCo Layered double hydroxides (LDHs) co-modified by Ir and V o were successfully prepared by the thermodynamically favorable galvanic replacement reaction. Electrochemical impedance spectroscopy confirmed that the synergistic effect of Ir and V o enhanced the charge transfer of FeCo LDHs. XPS spectra reveal robust interactions between Ir and FeCo LDHs. Density-functional theory further reveals that the low-oxygen-coordinated Ir (III) acts as an active site to optimize the OER rate-determining step energy barrier. As a result, Ir and V o co-modified FeCo LDH requires only a 203 mV overpotential to achieve a current density of 10 mA cm −2 and, more importantly, operates stably at an industrial current density of 250 mA cm −2 for 312 h without degradation. This work provides new insights and avenues for understanding the enhanced performance mechanism of catalysts after surface reconstruction and for industrial scale-up production.