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

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.