Optimization of carbon-supported Ir–Ru alloys for polymer electrolyte fuel cell anodes under cell reversal

Abstract Cell reversal (CR) caused by fuel starvation can significantly affect the performance of the polymer electrolyte membrane fuel cells (PEMFCs). To mitigate this issue, carbon-supported Ir–Ru alloys are considered as one of the most promising PEMFC anode materials. Herein, carbon-supported Ir–Ru alloys were prepared via a simple wet impregnation method followed by solid-state reduction at temperatures of 200, 250, and 300 ℃ under H2 gas flow and 300, 600, and 900 ℃ under N2 gas flow. The size, stoichiometric composition, and structural information of the prepared IrRu4/C were investigated using transmission electron microscopy, scanning electron microscopy–energy dispersive X-ray spectroscopy, X-ray diffraction, and X-ray absorption fine structure, the results of which exhibited different electrochemical properties in terms of hydrogen oxidation reaction and oxygen evolution reaction (OER). The electrochemical results showed the enhanced OER activities of IrRu4/C formed at 200 ℃ under H2. Furthermore, IrRu4/C can be formed under N2 with a change in the reduction temperature. This study provides fundamental properties for optimizing synthetic parameters of Ir–Ru-based catalysts to alleviate the degradation of conventional carbon-supported Pt owing to CR issues.