Electrochemical and hydraulic analysis of thin-film composite and cellulose triacetate membranes for seawater electrolysis applications
Electrochemical and hydraulic analysis of thin-film composite and cellulose triacetate membranes for seawater electrolysis applications
复制标题
用于海水电解应用的薄膜复合材料和三醋酸纤维素膜的电化学和水力分析
DOI：
10.1016/j.memsci.2023.121692
复制
发表时间：
2023
影响因子：
9.5
通讯作者：
Logan, Bruce E.
中科院分区：
文献类型：
--
作者：
Taylor, Rachel;Shi, Le;Zhou, Xuechen;Rossi, Ruggero;Picioreanu, Cristian;Logan, Bruce E.
聚合物过滤膜可以替代阳离子交换膜（CEMs）用于电解含阳极电解质和盐水阴极电解质，因为它们的尺寸选择性地阻碍了盐离子在隔室之间的传输，同时促进了质子和氢氧化物的传输。优化膜的性能需要更好地了解影响电阻和离子保留的膜特性。12个反渗透（RO）膜，1个纳滤（NF）膜和1个三醋酸纤维素正渗透（FO）膜在典型的CEMs表征条件下测试了它们的电阻。在低电流密度（0.07-0.3 mA cm - 2）下测量的电阻在不同膜之间的变化超过一个数量级，在1 M NaCl中，在中性pH下，从6.1±0.1 Ω cm2到70±30 Ω cm2。在20 mA cm−2的盐水电解过程中，膜电阻与外加电位之间没有显著的相关性（p = 0.44），膜电阻与水渗透性之间也没有显著的相关性（p = 0.35）。这些结果表明，传统的CEM电阻表征方法不能预测聚合物过滤膜的电解性能，因为质子和氢氧化物的传输在电解过程中很重要，当pH梯度较大时，必须将其与盐离子和水分子在电解过程中通过大小选择性RO、NF和FO膜的传输分开考虑。
Polymeric filtration membranes could be a cost-effective alternative to cation exchange membranes (CEMs) in electrolysis with a contained anolyte and saltwater catholyte because they size selectively hinder salt ion transport between compartments while facilitating proton and hydroxide transport. Optimizing membrane performance requires a better understanding of membrane properties that impact electrical resistances and ion retention. Twelve reverse osmosis (RO) membranes, one nanofiltration (NF) membrane, and one cellulose triacetate forward osmosis (FO) membrane were examined for their electrical resistances under conditions typically used for characterization of CEMs. Resistances measured at low current densities (0.07–0.3 mA cm−2) varied between different membranes by over an order of magnitude in 1 M NaCl at neutral pH, from 6.1 ± 0.1 Ω cm2to 70 ± 30 Ω cm2. There was no significant correlation between membrane resistance and applied potential during saltwater electrolysis at 20 mA cm−2(p = 0.44), or between membrane resistance and water permeability (p = 0.35). These results indicate that traditional CEM resistance characterization methods do not predict polymeric filtration membrane electrolysis performance because proton and hydroxide transport, which is important during electrolysis when large pH gradients develop, must be considered separately from salt ion and water molecule transport through size selective RO, NF, and FO membranes during water electrolysis.