Effect of humidity on the interaction of CO2 with alkaline anion exchange membranes probed using the quartz crystal microbalance
Effect of humidity on the interaction of CO2 with alkaline anion exchange membranes probed using the quartz crystal microbalance
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DOI：
10.1016/j.ijhydene.2017.07.142
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发表时间：
2017-09
影响因子：
7.2
通讯作者：
V. Bharath;J. Jervis;J. Bailey;Erik Engebretsen;T. Neville;J. Millichamp;T. Mason;P. Shearing;Richard J. C. Brown;G. Manos;D. Brett
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文献类型：
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作者：
V. Bharath;J. Jervis;J. Bailey;Erik Engebretsen;T. Neville;J. Millichamp;T. Mason;P. Shearing;Richard J. C. Brown;G. Manos;D. Brett
碱性阴离子交换膜燃料电池（AAEM-FC）在不使用贵金属电催化剂的情况下，能够提供与传统质子交换膜燃料电池（PEM-FC）相当的性能，使其成为低温燃料电池应用中更具成本竞争力的替代方案。然而，与降解有关的问题，特别是与二氧化碳的相互作用，仍然阻碍了该技术的商业化前景。由于水合作用在固体聚合物电解质燃料电池的运行中起着关键作用，本研究探讨了膜水合作用如何影响AAEM与CO2的相互作用。将暴露于大气co2时膜电导率的变化与铸膜离聚物粘弹性的变化进行了比较，两者都是湿度的函数。作为水合作用的一部分，co2对膜的影响表明，它与膜的溶剂化和溶胀机制有关，从而与co2进入膜内的离子通道有关。薄膜QCM复合谐振器研究表明，在溶剂化（开孔）过程中，随着水进一步渗透到孔系统中，阳离子头基变得越来越容易接近，co2的吸收量呈线性增加。在向孔隙膨胀状态过渡的过程中，由于网络被认为是完全开放的，二氧化碳的吸收量会逐步增加；因此，随后RH的增加不会导致co2吸收量的任何显著增加。
The alkaline anion exchange membrane fuel cell (AAEM-FC) is able to deliver a comparable performance to the traditional proton exchange membrane fuel cell (PEM-FC) without the use of precious metal electrocatalysts, making it a more cost-competitive alternative for low-temperature fuel cell applications. However, issues relating to degradation and specifically interaction with CO2still hinder the technology's commercialisation prospects. With hydration playing a key role in solid polymer electrolyte fuel cell operation, this study examines how membrane hydration affects the AAEM interaction with CO2. The change of membrane conductivity upon exposure to atmospheric CO2has been compared with the change in viscoelastic properties of a cast thin-film ionomer, both as a function of humidity. The effect of CO2on the membrane as a function of hydration suggests a link to its solvation and swelling regimes and thus the access of CO2to the ionic channels within the membrane. The thin-film QCM composite resonator study has suggested that during the solvation (pore opening) regime, there is a linear increase in CO2uptake as water can further permeate the pore system and the cationic headgroups become increasingly accessible. During the transition to the pore swelling regime, there is a step increase in CO2uptake as the network is thought to be fully open; as such, subsequent increases in RH do not lead to any significant increase in CO2uptake.