Anion-Environment-Controlled Synthesis of Ce-Doped NiFe LDH for Enhanced Activity and Stability in High-Current-Density Alkaline Oxygen Evolution

Hydrogen production in aqueous alkaline media is constrained by both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Here, we report an anion-environment-regulated synthesis strategy that enables uniform Ce incorporation into NiFe layered double hydroxides (LDHs) by replacing NH4F with NH4Cl during hydrothermal growth. The chloride precursor provides a milder coordination environment, enabling homogeneous Ce doping and improved charge transfer. The optimized NiFe0.95Ce0.05 LDH requires only a 307 mV overpotential to reach 1000 mA cm–2 in 1 M KOH. Raman spectroscopy, X-ray absorption spectroscopy, and density functional theory analyses indicate that Ce doping accelerates Ni oxidation and stabilizes β-NiOOH active species. When paired with a Ni&Ni0.2Mo0.8N cathode, the resulting anion exchange membrane electrolyzer (AEMWE) delivers 1 A cm–2 at 1.616 V and 8 A cm–2 at 2.185 V in 1 M KOH at 80 °C without iR compensation for high-current-density alkaline water electrolysis.