Interface Engineering Remarkably Improves the Stability of Fe‐Based Electrode for Alkaline Water Electrolysis at Industrial Ampere‐Level Current Density

ABSTRACT Iron‐based self‐supported electrocatalysts offer cost‐effective oxygen evolution activity but suffer from severe stability degradation under industrial operation. Here, we present that this long‐standing challenge can be solved by synergistic interface engineering, where a Fe nitride/oxide (NOIF) heterostructure interlayer that bridges active species and conductive substrate in Ni@NOIF is constructed. This innovative design simultaneously optimizes electron transfer and prevents active phase detachment, achieving long‐term industrial‐grade stability. Ni@NOIF sustains 1000 mA cm ⁻² for more than 370 h in 6 M KOH at 60°C (> 2000‐fold than Ni@IF). Practical validation in an industrial electrolyzer demonstrates the continuous stable operation for 170 h at ampere‐level current density. Mechanistic studies reveal that the Fe ₄ N/Fe ₃ O ₄ interface electronically modulates NiFeOOH active sites, while suppressing Ni/Fe leaching. This study establishes interface‐engineered Fe nitride/oxide interlayers as a stability promoter, providing a blueprint for durable electrocatalyst design in industrial hydrogen production.