Wakolo Solomon Wekesa, Tryk Donald A, Nishiyama Hiromichi, Miyatake Kenji, Iiyama Akihiro, Inukai Junji
Integrated Graduate School of Medicine, Engineering, and Agricultural Sciences, University of Yamanashi, 4-3-37 Takeda, Kofu, Yamanashi 400-8510, Japan.
Hydrogen and Fuel Cell Nanomaterials Research Center, University of Yamanashi, 6-43 Miyamae, Kofu, Yamanashi 400-0021, Japan.
Phys Chem Chem Phys. 2024 Jan 17;26(3):1658-1670. doi: 10.1039/d3cp03660j.
Anion exchange membrane fuel cells (AEMFCs) hold the key to future mass commercialisation of fuel cell technology, even though currently, AEMFCs perform less optimally than proton exchange membrane fuel cells (PEMFCs). Unlike PEMFCs, AEMFCs have demonstrated the capability to operate independently of Pt group metal-based catalysts. Water characterization inside the membrane is one factor that significantly influences the performance of AEMFCs. In this paper, different water species inside an anion exchange membrane (AEM), QPAF-4, developed at the University of Yamanashi, were studied for the first time using micro-Raman spectroscopy. Spectra of pure water, alkaline solutions, and calculations based on density functional theory were used to identify the water species in the AEM. The OH stretching band was deconvoluted into nine unique Gaussian bands. All the hydrogen-bonded OH species increased steadily with increasing humidity, while the CH and non-H-bonded OH remained relatively constant. These results confirm the viability of micro-Raman spectroscopy in studying the various water-related species in AEMs. The availability of this technique is an essential prerequisite in improving the ionic conductivity and effectively solving the persisting durability challenge facing AEMFCs, thus hastening the possibility of mass commercialisation of fuel cells.
阴离子交换膜燃料电池（AEMFCs）是燃料电池技术未来大规模商业化的关键，尽管目前AEMFCs的性能不如质子交换膜燃料电池（PEMFCs）。与PEMFCs不同，AEMFCs已证明能够独立于铂族金属基催化剂运行。膜内的水特性是显著影响AEMFCs性能的一个因素。本文首次使用显微拉曼光谱研究了山梨大学开发的阴离子交换膜（AEM）QPAF-4内的不同水物种。利用纯水、碱性溶液的光谱以及基于密度泛函理论的计算来识别AEM中的水物种。OH伸缩带被解卷积为九个独特的高斯带。随着湿度增加，所有氢键结合的OH物种稳步增加，而CH和非氢键结合的OH保持相对恒定。这些结果证实了显微拉曼光谱在研究AEM中各种与水相关物种方面的可行性。这项技术的可用性是提高离子电导率以及有效解决AEMFCs面临的持久耐久性挑战的重要前提条件，从而加速燃料电池大规模商业化的可能性。
