Cyclic Voltammetry as a Probe of Selective Ion Transport within Layered, Electrode-Supported Ion-Exchange Membrane Materials
Cyclic Voltammetry as a Probe of Selective Ion Transport within Layered, Electrode-Supported Ion-Exchange Membrane Materials
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循环伏安法作为层状电极支持离子交换膜材料内选择性离子传输的探针
DOI：
10.1149/1945-7111/ac51fd
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发表时间：
2022
影响因子：
3.9
通讯作者：
Korzeniewski, Carol
中科院分区：
文献类型：
--
作者：
Xu, Jiahe;Leddy, Johna;Korzeniewski, Carol
采用循环伏安法研究了电极支撑型离子交换聚合物膜的选择透过性能，该膜可用于双极膜的分子尺度光谱研究。通过使用可扩散的氧化还原探针分子[Ru（NH3）6] 3+和[IrCl 6] 2−，研究了薄离聚物膜组件排除与聚合物电荷相似的移动的离子（共离子）和积累与聚合物电荷相反的离子（抗衡离子）的能力。与阴离子交换膜（AEM）相支持的碳盘电极，通过添加阳离子交换膜（CEM）覆盖层形成的双极结表现出对氧化还原离子萃取和排斥的高选择性。对于使用Fumion® AEM相和Nafion®覆盖层形成的结，在Nafion®覆盖层之前交换到Fumion®中的[IrCl 6] 2−离子保持截留，并且Fumion®排除[Ru（NH 3）6] 3+离子，用于最终原位光谱测量的目标条件下的耐久性测试时间超过20小时。Sustainion®阴离子交换离聚物的实验发现了[IrCl 6] 2−离子与聚合物上的咪唑鎓侧基配位的证据。循环伏安法估计的有效扩散系数和平衡萃取常数的氧化还原活性探针离子在惰性，均匀密度的电极支撑的薄膜的电荷传输机制进行了研究。
Cyclic voltammetry was applied to investigate the permselective properties of electrode-supported ion-exchange polymer films intended for use in future molecular-scale spectroscopic studies of bipolar membranes. The ability of thin ionomer film assemblies to exclude mobile ions charged similarly to the polymer (co-ions) and accumulate ions charged opposite to the polymer (counterions) was scrutinized through use of the diffusible redox probe molecules [Ru (NH 3) 6] 3+ and [IrCl 6] 2−. With the anion exchange membrane (AEM) phase supported on a carbon disk electrode, bipolar junctions formed by addition of a cation exchange membrane (CEM) overlayer demonstrated high selectivity toward redox ion extraction and exclusion. For junctions formed using a Fumion® AEM phase and a Nafion® overlayer,[IrCl 6] 2− ions exchanged into Fumion® prior to Nafion® overcoating remained entrapped and the Fumion® excluded [Ru (NH 3) 6] 3+ ions for durability testing periods of more than 20 h under conditions of interest for eventual in situ spectral measurements. Experiments with the Sustainion® anion exchange ionomer uncovered evidence for [IrCl 6] 2− ion coordination to pendant imidazolium groups on the polymer. A cyclic voltammetric method for estimation of the effective diffusion coefficient and equilibrium extraction constant for redox active probe ions within inert, uniform density electrode-supported thin films was applied to examine charge transport mechanisms.