Effect of titanium-based supports on the electrochemical activity and stability of iridium nanoparticle catalysts for OER in PEM water electrolyzer

[EN] Efficient and stable oxygen evolution reaction catalysts are essential for advancing hydrogen production through water electrolysis. This study investigates the role of titanium-based supports ¿ TiO2, TiC, and TiN ¿ in enhancing the activity and stability of iridium (Ir) nanoparticles, focusing on their morphological, chemical, and electrochemical properties. In a half-electrochemical cell, iridium supported on titanium dioxide (Ir/TiO2) and titanium carbide (Ir/TiC) exhibited excellent OER performance with an overpotential of 260 mV and 259 mV at 10 mA cm¿ 2 , respectively, which are comparable to unsupported Ir black nanoparticles (253 mV). In contrast, Ir supported on titanium nitride (Ir/TiN) showed a higher overpotential of 329 mV. The catalytic performance of these materials was further evaluated in a single-cell proton exchange membrane water electrolyzer. Postmortem analyses of the membrane electrode assemblies revealed support-specific degradation pathways, including oxidation and dissolution processes. The findings highlight the influence of support material properties ¿ such as conductivity, crystallinity, and composition ¿ on the efficiency and durability of Ir nanoparticles. These insights provide a valuable foundation for designing advanced catalytic materials for water electrolyzers.