The dual role of iron incorporated oxygen evolution catalysts in balancing activity and durability of anion exchange membrane electrolyzers

The performance-durability trade-off in iron-doped anodes remains a key bottleneck for anion exchange membrane water electrolyzers (AEMWE). Through a systematic investigation of the NiCo 2 Fe x catalysts, we reveal that Fe content produces a fundamental trade-off: cell activity follows a volcano-type dependence, while operational durability decreases monotonically. The NiCo 2 Fe 0.5 anode shows an optimal balance, delivering a cell voltage of 1.95 V at 2.0 A cm −2 and maintaining robust performance for 2400 h under dynamic, intermittent conditions. Mechanistic studies attribute this to Fe-regulated surface reconstruction, wherein controlled doping stabilizes an active NiCo(Fe)OOH phase, whereas over-doping triggers rapid degradation via cation dissolution. This work reveals the mechanism of Fe's dual role and establishes precise doping optimization as the guiding principle for developing stable, high-efficiency AEMWE technology. • Revealed the mechanism of optimal Fe content mismatch for activity and stability. • Fe's dual role: optimal doping stabilizes active phase, excess causes dissolution. • NiCo 2 Fe 0.5 anode achieves 2 A cm −2 at 1.95 V and 2400 h stable operation. • Ultra-low degradation rate of 32 μV h −1 under dynamic intermittent conditions.