Proton conductivity and durability of Ce-based hybrid proton exchange membranes synchronously enhanced by dual-function γ-AlOOH@Ti-supported CeO2 composite oxide

• Published in: Journal of power sources Vol. 623; p. 235498
• Main Authors: Liu, Hongsheng, Li, Hengyue, Huang, Bin, Yang, Yange, Guo, Haibo, Xiao, Yan, Yang, Weiguang
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.12.2024
• Subjects: Ce-based proton exchange membrane; Chemical stability; Dual-function; Proton conductivity; γ-AlOOH; Ce-based proton exchange membrane; Proton conductivity; Dual-function; Chemical stability; γ-AlOOH
• ISSN: 0378-7753
• DOI: 10.1016/j.jpowsour.2024.235498

To enhance the proton conductivity and durability of Ce-based hybrid proton exchange membranes (PEMs), this study fabricates modified perfluorosulfonic acid (PFSA) hybrid membranes by incorporating the dual-function γ-AlOOH@Ti-supported CeO2 composite oxide (γ-AlOOH@Ti/CeO2). In addition to combining the inherent proton conductivity of γ-AlOOH with the excellent radical scavenging ability of CeO2, both the proton conductivity and durability of Ce-based PEMs are further improved by introducing Ti-dopant, which not only increases hydrogen vacancies on the surface of γ-AlOOH, which facilitate proton conduction, and induces electron transfer from γ-AlOOH@Ti to CeO2, which enhance free radical adsorption. As results shown, the proton conductivity and the fluoride release value of the resulting hybrid membrane are about 76 % higher and 35.25 % lower than those of the PFSA-CeO2 membrane, respectively. Moreover, the performance of cells shows that, after accelerated degradation testing, the PFSA-γ-AlOOH@Ti/CeO2 membrane exhibits the lowest peak power density decrease rate, the impedance increase rate and hydrogen crossover current density, with 11.79 %, 27.54 % and 3.04 mA cm−2, respectively. These results suggest that compared to CeO2-hybrid PEMs, γ-AlOOH@Ti/CeO2-based hybrid PEMs exhibit higher proton conductivity and superior chemical stability, indicating the potential application of γ-AlOOH@Ti/CeO2-based hybrid PEMs in proton exchange membrane fuel cells. •OH-rich surface of AlOOH and Ti-dopant effectively facilitate proton conduction.•Ti-induced electron transfer effect enhances free radical scavenging ability.•The decrease rate of peak power density of the obtained PEMFC is only 11.79 %.•DFT calculations investigate the origins of experimental trends.