Enriching Edge‐Structures of NiFe‐LDH via Ru─Ni Site Interchange as Efficient and Stable OER Catalytic Electrodes

Abstract Nickel‐iron layered double hydroxide (NiFe‐LDH) has emerged as a highly promising electrocatalyst for the alkaline oxygen evolution reaction (OER) due to its tunable electronic structure and cost‐effectiveness. However, its intrinsic catalytic activity is predominantly governed by the limited exposure of edge‐active sites, which are inherently constrained by its 2D sheet‐like morphology. Here, Ru/NiFe‐LDH/CuO with abundant edge sites is synthesized through a low‐temperature hydrothermal cation exchange process. The introduction of Ru atoms not only modulates the local coordination environment of Ni and Fe centers but also optimizes the electronic structure, thereby enhancing the synergistic interplay among Ru─Ni─Fe triple sites and significantly improving both the OER activity and long‐term stability. The Ru/NiFe‐LDH/CuO electrocatalyst exhibits exceptional performance, requiring overpotentials of only 211 and 300 mV to achieve current densities of 10 and 500 mA cm −2 , respectively. Moreover, it maintains stable operation at a current density of 500 mA cm −2 for 500 h without significant deterioration. Density functional theory (DFT) calculations further reveal that introduction of Ru effectively lowers the energy barrier for the rate‐determining step and stabilizes the edge‐exposed Fe sites, thereby elucidating the origin of the enhanced intrinsic activity. This work provides a facile and effective strategy for engineering high‐performance NiFe‐LDH‐based OER electrocatalysts.