A Robust Squarate-Based Metal-Organic Framework Demonstrates Record-High Affinity and Selectivity for Xenon over Krypton
A Robust Squarate-Based Metal-Organic Framework Demonstrates Record-High Affinity and Selectivity for Xenon over Krypton
复制标题
坚固的方形金属有机框架对氙比氪表现出创纪录的高亲和力和选择性
DOI：
10.1021/jacs.9b03422
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发表时间：
2019-06-12
影响因子：
15
通讯作者：
Li, Jing
中科院分区：
文献类型：
--
作者：
Li, Liangying;Guo, Lidong;Li, Jing
氙（Xe）和氪（Kr）的有效分离是工业上重要的工艺之一。虽然这两种物质的吸附分离被认为是一种节能的方法，但开发高选择性吸附剂仍然具有挑战性。在本文中，具有与Kr的动力学直径（4.047埃）相当的完美孔径（4.1埃× 4.3埃）以及用非常极性的羟基修饰的孔表面的刚性的基于方酸盐的金属-有机框架（MOF）能够有效地区分Kr原子，提供创纪录高的Kr/Kr选择性。在环境温度下，在低压（0.2巴）下获得了58.4 cm（3）/cm（3）的特别高的吸收能力和60.6的选择性。在迄今为止报道的所有最先进的吸附剂中，MOF表现出最高的Kr亨利系数（192.1 mmol/g/bar）和Kr/Kr亨利选择性（54.1）。直接穿透实验进一步证实了其优异的分离性能。密度泛函理论计算表明，最佳孔径和极性孔隙率之间的协同作用的结果之间的强相互作用的骨架和嵌段共聚物。
The efficient separation of xenon (Xe) and krypton (Kr) is one of the industrially important processes. While adsorptive separation of these two species is considered to be an energy efficient process, developing highly selective adsorbent remains challenging. Herein, a rigid squarate-based metal-organic framework (MOF), having a perfect pore size (4.1 angstrom x 4.3 angstrom) comparable with the kinetic diameter of Xe (4.047 angstrom) as well as pore surface decorated with very polar hydroxyl groups, is able to effectively discriminate Xe atoms, affording a record-high Xe/Kr selectivity. An exceptionally high Xe uptake capacity of 58.4 cm(3)/cm(3) and selectivity of 60.6 at low pressure (0.2 bar) are achieved at ambient temperature. The MOF exhibits the highest Xe Henry coefficient (192.1 mmol/g/bar) and Xe/Kr Henry selectivity (54.1) among all state-of-the-art adsorbents reported so far. Direct breakthrough experiments further confirm the excellent separation performance. The density functional theory calculations reveal that the strong interaction between Xe and the framework is a result of the synergy between optimal pore size and polar porosity.