An Anion-Regulation Strategy for Scalable Fe-Rich NiFe Electrodes With Disorder Lattices Toward Industrial Water...

Elevating Fe-involved sites in NiFe catalysts can accelerate water-oxidation kinetics, but it remains challenging to fabricate scalable, durable Fe-rich NiFe-based electrodes. We demonstrate that anion regulation is an effective and scalable strategy for fabricating Fe-rich NiFe catalysts with improved catalytic activity and durability. The Fe content has increased by 70%-90% in the NiFe layer deposited in a chloride-type electrolyte relative to a sulfate-type electrolyte. The Fe-rich electrode exhibits an overpotential of 243 mV@100 mA cm^-2 and demonstrates excellent stability for 100 h at 1000 mA cm^-2. Scaling electrodes to 10 × 10 cm² and implementing them in an industrial-level anion-exchange membrane water electrolysis (AEMWE) with 14 cells, it achieves a voltage of 2.0 V@1500 mA cm^-2 and a stable voltage of 1.74 V@500 mA cm^-2 for over 200 h. A key insight from EXAFS and in situ Raman reveals that the Fe-rich electrode exhibits pronounced coordination defects and greater lattice disorder. DFT calculations also indicate that increasing the Fe content reduces the binding energy of ^*O by NiFeOOH. This study presents a practical approach to enhancing the activity and stability of NiFe electrodes, demonstrating potential for large-scale applications of AEMWEs.