Using reverse osmosis membranes to control ion transport during water electrolysis
Using reverse osmosis membranes to control ion transport during water electrolysis
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DOI：
10.1039/d0ee02173c
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发表时间：
2020-09
影响因子：
32.5
通讯作者：
Le Shi;R. Rossi;M. Son;Derek M. Hall;M. Hickner;C. Gorski;B. Logan
中科院分区：
文献类型：
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作者：
Le Shi;R. Rossi;M. Son;Derek M. Hall;M. Hickner;C. Gorski;B. Logan
由于太阳能和风能发电成本的降低，以及避免化石燃料排放二氧化碳的需要，人们对水电解制氢的兴趣日益浓厚。利用海水和可再生电力生产近海和沿海氢气是一个特别有趣的方法，但由于离子交换膜的高成本和现有电解槽设计中需要淡化海水，目前在经济上是不可行的。本文描述了一种新的方法，该方法使用相对便宜的市售膜，用于反渗透（RO），以选择性地运输有利离子。在外加电场中，反渗透膜具有相当大的质子和氢氧化物通过活性层的传输能力，同时排除盐阴离子和阳离子。高氯酸盐被用来提供一种惰性和含有阳极电解质，通过质子和氢氧化物离子流通过反渗透膜来平衡电荷。使用合成海水（NaCl）作为阴极电解质，在那里它提供连续的氢气释放。在1 M NaCl条件下，反渗透膜的电阻为21.7±3.5 Ω cm2，在10-40 mA cm - 2的电流密度下，在模型电解池中分解水所需的电压与使用两种常用的、更昂贵的离子交换膜时的电压相当。
The decreasing cost of electricity produced using solar and wind and the need to avoid CO2 emissions from fossil fuels has heightened interest in hydrogen gas production by water electrolysis. Offshore and coastal hydrogen gas production using seawater and renewable electricity is of particular interest, but it is currently economically infeasible due to the high costs of ion exchange membranes and the need to desalinate seawater in existing electrolyzer designs. A new approach is described here that uses relatively inexpensive commercially available membranes developed for reverse osmosis (RO) to selectively transport favorable ions. In an applied electric field, RO membranes have a substantial capacity for proton and hydroxide transport through the active layer while excluding salt anions and cations. A perchlorate salt was used to provide an inert and contained anolyte, with charge balanced by proton and hydroxide ion flow across the RO membrane. Synthetic seawater (NaCl) was used as the catholyte, where it provided continuous hydrogen gas evolution. The RO membrane resistance was 21.7 ± 3.5 Ω cm2 in 1 M NaCl and the voltages needed to split water in a model electrolysis cell at current densities of 10–40 mA cm−2 were comparable to those found when using two commonly used, more expensive ion exchange membranes.