Robust and efficient Fe-doped NiMo@NF catalyst for high performance anion exchange membrane water electrolysis

Abstract

Anion exchange membrane (AEM) water electrolysis is a promising technology for hydrogen production; however, the electrochemical stress during long-term operation at high current densities can pose challenges for non-precious metal catalysts, leading to performance degradation. In this study, we synthesized a Fe-doped NiMo@nickel foam (NF) catalyst via simple hydrothermal and immersion processes. The catalyst exhibited nanorod morphology with a high surface area, enhancing electrochemical activity while maintaining structural stability. Electrochemical and physical characterizations revealed that Mo leaching during the oxygen evolution reaction (OER) facilitated appropriate catalyst activation. The Fe-doped NiMo@NF catalyst exhibited a low overpotential of 296 mV at 100 mA cm−2 in a three-electrode system and maintained stable performance over 50 h of continuous operation, highlighting its potential as a durable and efficient non-precious OER catalyst. Furthermore, in an AEM single-cell test with a commercial PiperION membrane, it delivered a high current density of 830 mA cm−2 at 2.0 V, and also exhibited excellent stability under a constant applied current of 0.5 A for over 58 h of continuous operation. These results indicate that the Fe-doped NiMo@NF catalyst is a highly stable and efficient alternative for AEM electrolysis under harsh operating conditions. © 2025 Hydrogen Energy Publications LLC