Dual Single-Atom Anchored on Oxygen Vacancy of CoFe-LDH for Highly Stable Electrochemical Water Oxidation

Heterogeneous single-atom doping is an effective strategy to modulate electronic structures and thereby enhance the electrocatalytic performance of catalysts. In this study, Ru and Ir single atoms are anchored onto the CoFe-LDH lattice via oxygen-vacancy defects to construct a dual single-atom catalyst (DSAC). The Ru, Ir@CoFe-LDH (Layered Double Hydroxide)/IF (Iron Foam) electrode exhibits outstanding oxygen evolution reaction (OER) activity in alkaline media, achieving a current density of 500 mA cm^{- 2} at an overpotential of only 299 ± 3.6 mV. Turnover frequency (TOF) analysis confirms that the dual single-atom sites deliver superior intrinsic activity per active site. Notably, the catalyst demonstrates exceptional durability, exhibiting nearly negligible activity loss after 1033 h (@500 mA cm^{- 2}) of continuous operation under industrial-level conditions. Density functional theory (DFT) calculations reveal that the d-band centers of oxygen-vacancy-anchored Ru and Ir are closer to the Fermi level, thereby optimizing the adsorption-desorption energetics of oxygen intermediates and fundamentally accounting for the enhanced activity. This study provides a feasible strategy for the rational design of high-performance and durable electrocatalysts through precise modulation of electronic structures and active-site configurations in multi-metallic systems.