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

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 degrees C under H-2 gas flow and 300, 600, and 900 degrees C under N-2 gas flow. The size, stoichiometric composition, and structural information of the prepared IrRua/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 IrRua/C formed at 200 degrees C under H-2. Furthermore, IrRua/C can be formed under N-2 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. (C) 2020 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.