Hydroxide Anion Transport in Covalent Organic Frameworks.
Hydroxide Anion Transport in Covalent Organic Frameworks.
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共价有机框架中的羟基阴离子传输。
DOI：
10.1021/jacs.1c03268
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发表时间：
2021
影响因子：
15
通讯作者：
D. Jiang
中科院分区：
文献类型：
--
作者：
Shanshan Tao;Hong Xu;Qing Xu;Y. Hijikata;Qiuhong Jiang;S. Irle;D. Jiang
氢氧化物阴离子的传输对于碱性燃料电池是必不可少的，但是氢氧化物阴离子由于其小的扩散系数和高质量而具有固有的低电导率。在共价有机框架中发现的有序开放通道是有前途的，使氢氧阴离子运输的途径，但这仍有待探索。在这里，我们报告设计合成的阴离子共价有机框架，促进氢氧化物阴离子运输通过一维通道。将具有咪唑鎓末端的阳离子链工程化到孔壁上，在通道中自组装单列氢氧化物阴离子链的超分子界面。该框架有助于氢氧根阴离子的传输，在80 °C下实现1.53 × 10-2 S cm-1的优异电导率，这比线性聚合物和其他多孔框架高2-6个数量级。在不同温度下的阻抗谱和氘代样品的研究表明，氢氧阴离子通过质子交换跳跃机制传输。这些结果开辟了一种方法来设计框架材料的能量转换通过工程的阴离子界面。
Hydroxide anion transport is essential for alkaline fuel cells, but hydroxide anion has an inherently low conductivity owing to its small diffusion coefficient and high mass. Ordered open channels found in covalent organic frameworks are promising as pathways to enable hydroxide anion transport, but this remains to be explored. Here we report designed synthesis of anionic covalent organic frameworks that promote hydroxide anion transport across the one-dimensional channels. Engineering cationic chains with imidazolium termini onto the pore walls self-assembles a supramolecular interface of single-file hydroxide anion chains in the channels. The frameworks facilitate hydroxide anion transport to achieve an exceptional conductivity of 1.53 × 10-2 S cm-1 at 80 °C, which is 2-6 orders of magnitude higher than those of linear polymers and other porous frameworks. Impedance spectroscopy at different temperatures and studies on deuterated samples reveal that hydroxide anions transport via a proton-exchange hopping mechanism. These results open a way to design framework materials for energy conversions via engineering an anionic interface.