Ultrathin IrRu nanowire networks with high performance and durability for the hydrogen oxidation reaction in alkaline anion exchange membrane fuel cells

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Vol. 6; no. 41; pp. 20374 - 20382
• Main Authors: Qin, Bowen, Yu, Hongmei, Gao, Xueqiang, Yao, Dewei, Sun, Xinye, Song, Wei, Yi, Baolian, Shao, Zhigang
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 2018
• Subjects: Anion exchange; Anion exchanging; Anodes; Catalysis; Catalysts; Chemical reduction; Durability; Electrochemistry; Fuel cells; Fuel technology; Iridium; Nanotechnology; Nanowires; Organic chemistry; Oxidation; Ruthenium; Ruthenium compounds; Sodium
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/C8TA07414C

Developing highly active and stable HOR catalysts still remains a challenging task for alkaline anion exchange membrane fuel cells. A carbon supported IrRu nanowire catalyst with different compositions was prepared by a soft template method, involving the chemical reduction of iridium and ruthenium complexes using sodium borohydride. The Ir 1 Ru 1 ultrathin nanowires exhibit higher hydrogen oxidation activity and better stability under alkaline conditions in comparison with commercial Pt/C. An electrochemical test demonstrates that the mass and specific activities at an over potential of 50 mV of Ir 1 Ru 1 NWs/C are 4.2 and 3.8 times that of commercial Pt/C, respectively. Furthermore, the synthesized Ir 1 Ru 1 NWs display better stability against potential cycling due to their unique interconnected structure. After 2000 potential cycles, the electrochemically active surface area (ECSA) of Ir 1 Ru 1 NWs/C reduces only by 2.27%, and the mass activity@50 mV is reduced by 8.21%. The single cell used the as-prepared Ir 1 Ru 1 NWs/C as the anode catalyst and Pt/C as the cathode catalyst, and the AAEMFC shows a peak power density of more than 485 mW cm −2 , which is about 1.66 fold that of the AAEMFC using commercial Pt/C as the anode catalyst (292 mW cm −2 ). These results suggest that carbon supported ultrathin Ir 1 Ru 1 NW catalysts can be used as substitutes for commercial Pt/C for the HOR in alkaline media for alkaline anion exchange membrane fuel cell application.