State Key Laboratory of Chemical Resource Engineering, Institute of Modern Catalysis, Department of Organic Chemistry, School of Science, Beijing University of Chemical Technology, Beijing, 100029, P. R. China.
Nanoscale. 2018 Oct 21;10(39):18680-18689. doi: 10.1039/c8nr06048g. Epub 2018 Sep 28.
Concentrating on the ion conductivity of anion exchange membranes (AEMs), we present a magnetic-field-oriented strategy to address the insufficient ion conductivity and the lifetime problem of AEMs used in alkali membrane fuel cells (AMFCs). Magnetic ferroferric oxide (FeO) is functionalized with quaternary ammonium (QA) groups to endow the QA-FeO with ion-exchange ability. A series of aligned QA-FeO/poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) hybrid membranes were fabricated by doping QA-FeO in a triple-ammonium-functionalized PPO (TA-PPO) solution in an applied magnetic field. The structure of aligned QA-FeO in the TA-PPO membrane is clearly observed by using a scanning electron microscope (SEM). More importantly, the aligned QA-FeO constructs successive and effective ion-transport channels in the QA-FeO/TA-PPO membrane, which dramatically improves the ion conductivity of the membranes. Notably, the magnetic-field-induced ion channels (MICs) are different from microscopic phase-induced ion channels (PICs). These MICs display much shorter ion transport distances and broader water channels than traditional PICs in AEMs. The aligned QA-FeO/TA-PPO hybrid membrane displays a further 55% increase in ion conductivity after magnetic-field orientation compared to the normal QA-FeO/TA-PPO membrane. Surprisingly, the aligned QA-FeO also improves the alkali stability and fuel cell performance of the hybrid membrane. The aligned 6%-QA-FeO/TA-PPO hybrid membrane realizes a maximal power density of 224 mW cm. In summary, this work provides a novel and effective method to prepare high-performance AEMs.
专注于阴离子交换膜 (AEM) 的离子电导率，我们提出了一种磁场导向策略，以解决用于碱膜燃料电池 (AMFC) 的 AEM 离子电导率不足和寿命问题。磁性四氧化三铁 (FeO) 用季铵 (QA) 基团官能化，使 QA-FeO 具有离子交换能力。通过在施加磁场的情况下将 QA-FeO 掺杂到三铵官能化的聚 (2,6-二甲基-1,4-苯撑氧化物) (TA-PPO) 溶液中，制备了一系列对齐的 QA-FeO/聚 (2,6-二甲基-1,4-苯撑氧化物) (PPO) 杂化膜。通过扫描电子显微镜 (SEM) 可以清楚地观察到 TA-PPO 膜中对齐的 QA-FeO 结构。更重要的是，对齐的 QA-FeO 在 QA-FeO/TA-PPO 膜中构建了连续有效的离子传输通道，这极大地提高了膜的离子电导率。值得注意的是，磁场诱导的离子通道 (MIC) 与 AEM 中的微观相诱导离子通道 (PIC) 不同。与传统 AEM 中的 PIC 相比，这些 MIC 具有更短的离子传输距离和更宽的水通道。与正常 QA-FeO/TA-PPO 膜相比，磁场取向后对齐的 QA-FeO/TA-PPO 杂化膜的离子电导率进一步提高了 55%。令人惊讶的是，对齐的 QA-FeO 还提高了杂化膜的碱性稳定性和燃料电池性能。对齐的 6%-QA-FeO/TA-PPO 杂化膜实现了 224 mW cm 的最大功率密度。总之，这项工作提供了一种制备高性能 AEM 的新方法。
