Direct seawater electrolysis via synergistic acidification by inorganic precipitation and proton flux from bipolar membrane
Direct seawater electrolysis via synergistic acidification by inorganic precipitation and proton flux from bipolar membrane
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DOI：
10.1016/j.cej.2021.132383
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发表时间：
2021-09-15
影响因子：
15.1
通讯作者：
Chung, Taek Dong
中科院分区：
文献类型：
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作者：
Han, Ji-Hyung;Jwa, Eunjin;Chung, Taek Dong
该报告描述了直接海水电解（DSE），其中天然海水用作阴极电解液而不进行过滤或预处理;海水被酸化至pH 2，同时通过析氢反应（HER）在阴极处产生氢氧根离子。它是由阴极无机沉淀捕获的氢氧离子和双极膜（BPM;用作分离器）中水解离产生的质子通量的协同效应引起的。所提出的BPM-DSE中阴极电解液的酸化基本上减轻了阴极钝化，消除了对用于处理分散在阴极电解液中的无机沉淀物的额外工艺的要求，并且降低了HER所需的阴极电位（Ec）以实现长期DSE。该系统中的BPM在维持电解质浓度、抑制析氯反应（ClER）和使析氧反应最大化方面起关键作用。这些发现有望为DSE的大规模运行带来突破，成功克服能耗、无机沉淀、ClER和腐蚀等挑战。
This report describes direct seawater electrolysis (DSE) wherein natural seawater is used as a catholyte without filtration or pretreatment; seawater is acidified to a pH of 2 while hydroxide ions are produced at the cathode by the hydrogen evolution reaction (HER). It results from the cooperative effect of hydroxide ions trapped through inorganic precipitation at the cathode and proton flux from water dissociation in a bipolar membrane (BPM; used as a separator). The acidification of the catholyte in the proposed BPM-DSE substantially mitigates cathode passivation, eliminates the requirement of additional processes for treatment of inorganic precipitates dispersed in the catholyte, and reduces the cathode potential (Ec) required for the HER to enable long-term DSE. The BPM in this system plays a critical role in maintaining the electrolyte concentration, suppressing the chlorine evolution reaction (ClER), and maximizing the oxygen evolution reaction. These findings are expected to suggest a breakthrough toward large-scale operation of DSE that successfully overcomes challenges such as energy consumption, inorganic precipitation, ClER, and corrosion.