Praseodymium-Modulated NiFe Layered Double Hydroxide with Enhanced Oxygen Evolution Activity and Extended Durability

The oxygen evolution reaction (OER) in alkaline water electrolysis suffers from sluggish kinetics and limited catalyst durability. Here, we present a praseodymium (Pr) doping strategy that simultaneously tailors the electronic structure and pore architecture of nickel-iron layered double hydroxide (NiFe-LDH). Atomically dispersed Pr³⁺ expands the interlayer spacing from 0.76 to 0.81 nm and refines the mesoporous network, increasing Brunauer-Emmett-Teller (BET) surface area by 13.4% and decreasing the average BJH desorption pore size by 12.8%. Strong Pr─O covalency downshifts the Ni 3d band center and reinforces Ni─O hybridization, as corroborated by X-ray absorption spectroscopy and density functional theory (DFT). These synergistic effects switch the OER rate-determining step (RDS) from ^*O → ^*OOH (ΔG = 0.74 eV) to ^*OH → ^*O (ΔG = 0.28 eV). The optimized Ni₂Fe_0.88Pr_0.12-LDH delivers an overpotential of 407 mV at 500 mA cm^-2 and sustains 2190 h in half-cell tests. When integrated into an anion exchange membrane (AEM) electrolyzer, it operates continuously for over 1000 h at industrially relevant current densities, with a moderate voltage drift of 0.202 V (average degradation rate ∼0.20 mV h^-1). This work establishes a dual electronic and pore engineering route for durable LDH-based OER catalysts.