Alkaline anion exchange membrane degradation as a function of humidity measured using the quartz crystal microbalance
Alkaline anion exchange membrane degradation as a function of humidity measured using the quartz crystal microbalance
复制标题
DOI：
10.1016/j.ijhydene.2017.01.158
复制
发表时间：
2017-03-02
影响因子：
7.2
通讯作者：
Brett, D. J. L.
中科院分区：
文献类型：
--
作者：
Bharath, V. J.;Jervis, R.;Brett, D. J. L.
固体聚合物电解质（SPE）碱性阴离子交换膜（AAEM）燃料电池具有容易的氧还原反应（ORR）动力学，并具有利用非贵金属电催化剂的能力。然而，据报道，AAEM在碱性介质中的不稳定性增加（降解），通过许多途径，包括在高于60 ℃的温度下操作时的亲核消除，在一定程度上消除了在较高温度下操作的动力学优势。尽管如此，模拟研究表明，膜水化可以显示出改善的耐碱性不稳定性和随后的降解时，在高温下操作。本研究使用石英晶体微天平（QCM）来检查商业AAEM的热稳定性作为湿度的函数。结果表明，水合提高了离聚物对降解的抗性，因为系统内的离子（即OH-亲核试剂和阳离子头基）变得反应性较低。在线质谱数据证实，离聚物在本研究中使用的高温偏移期间降解。(C)2017年氢能出版有限责任公司。由爱思唯尔有限公司出版。保留所有权利。
The solid polymer electrolyte (SPE) alkaline anion exchange membrane (AAEM) fuel cell exhibits facile oxygen reduction reaction (ORR) kinetics and has the ability to utilise non precious metal electrocatalysts. However, the AAEM is reported to suffer from increased instability within the alkaline media (degradation) via a number of routes, including nucleophilic elimination when operated at temperatures above 60 degrees C, somewhat eliminating the kinetic advantage of operating at higher temperatures. Nonetheless, modelling studies have indicated that the membrane hydration could show improved resistance to alkaline instability and subsequent degradation when operated at elevated temperatures. This investigation uses the quartz crystal microbalance (QCM) to examine the thermal stability of a commercial AAEM as a function of humidity. The results show that hydration improves ionomer resistance to degradation, as the ions within the system (namely the OH- nucleophile and cationic headgroups) become less reactive. In-line mass spectrometry data confirms that the ionomer degrades during the elevated temperature excursions used in this study. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.