Enhanced oxygen evolution reaction performance and reduced iridium loading of Ni-dealloyed IrNix catalysts designed for proton exchange membrane water electrolyzers

초록

The cost and durability limitations of iridium-based oxygen evolution reaction (OER) catalysts designed for proton exchange membrane water electrolyzers (PEMWEs) should be addressed to accelerate green hydrogen economy. In this study, the OER performance, Ir loading (Irloading), and durability of Ni-dealloyed IrNix applied PEMWEs (ND-IrNix-PEMWEs) are measured and compared to those of conventional IrO2-PEMWE. ND-IrNix-PEMWEs are developed using a dealloying strategy that leverages Ni as a sacrificial component. The transient behavior of the ND-IrNi1.93-PEMWE during in situ Ni dealloying is analyzed to evaluate its impact on the OER performance. Despite a reduced amount of Irloading, the ND-IrNi1.93-PEMWE exhibits 42.9% higher current density and 4.2-fold greater catalytic activity at 1.7 V than a commercial IrO2-PEMWE. Moreover, based on the long-term durability test over 100 h, the degradation rate of the ND-IrNi1.93-PEMWE is 58.6% lower than that of the IrO2-PEMWE because of the suppression of structural degradation, including the particle coarsening and agglomeration. Additionally, the ND-IrNi1.93-PEMWE achieves a lower Ir-specific power density while maintaining a reduced Irloading. This study demonstrates that the ND-IrNi1.93-PEMWE is a promising candidate for replacing conventional IrO2-PEMWE, offering high OER performance and improved durability with significantly reduced Irloading.

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