Tetrahedral CdO ₄ Hinge‐Stabilized NiFe‐Layered Double Hydroxide for Ultra‐Stable Ampere‐Level Alkaline Water Oxidation

Abstract Nickel‐iron layered double hydroxides are promising non‐precious electrocatalysts for oxygen evolution reaction. However, the inherent instability caused by Fe dissolution limits their practical application. Here, an innovative interlayer molecular‐like hinge strategy utilizing tetrahedral CdO 4 units is introduced to fixate the layered structure, effectively mitigating Fe segregation and achieving unprecedented durability. Combined experimental and theoretical investigations reveal that the CdO 4 acting as a molecular‐like hinge establishes robust Cd‐O‐M (M = Ni, Fe) bridges within the interlayer. This unique configuration not only strengthens the M─O bonding interactions but facilitates efficient electron transfer. Crucially, under anodic polarization, Cd‐mediated electron redistribution elevates the oxidation states of the M centers, significantly enhances the covalency of the Fe─O bonds, and anchors Fe species. Accordingly, Co 1.5 Ni(OH) x @NiFe(Cd) LDH exhibits exceptional stability: operates continuously for over 200 h at 600 mA cm −2 (2.1 V vs RHE) in standard alkaline electrolyte, and maintains performance under industrially more demanding conditions—simulated seawater (800 mA cm −2 @ 2 V, 200 h) and strong alkaline solution (1000 mA cm −2 @ 2 V, 200 h). Furthermore, it exhibits a low overpotential of 192 mV at 10 mA cm −2 . This work establishes a novel structural fixation paradigm for developing ultra‐stable NiFe‐based catalysts meeting industrial‐current‐density demands.