Zhu Xiaoqian, Ke Tian, Han Pei, Zhang Zhiguo, Bao Zongbi, Yang Yiwen, Ren Qilong, Yang Qiwei
Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, Zhejiang, China.
Institute of Zhejiang University-Quzhou, Quzhou 324000 Zhejiang, China.
J Am Chem Soc. 2024 Sep 11;146(36):24956-24965. doi: 10.1021/jacs.4c06354. Epub 2024 Aug 5.
Adsorptive separation of Xe and Kr is an industrially promising but challenging process because of their identical shape and similar physicochemical properties. Herein, we demonstrate a strategy through rationally designing the linkers of anionic functional ultramicroporous materials (FUMs) to finely regulate the pore chemistry and architecture, which creates unique stepped channels incorporating dense polar nanotraps to generate a larger effective pore space and enables dense packing of Xe. A new hydrolytically stable FUM (ZUL-530) was prepared, which for the first time achieves a Xe packing density exceeding the liquid Xe density at atmospheric conditions in metal-organic frameworks (MOFs) (based on experimental data), resulting in both excellent Xe uptake (2.55 mmol g at 0.2 bar) and high IAST selectivity (20.5). GCMC and DFT-D calculations reveal the essential role of the stepped traps in the dense packing of Xe. Breakthrough experiments demonstrate remarkable productivities of both high-purity Kr (6.70 mmol g) and Xe (1.78 mmol g) for the Xe/Kr (20:80) mixture. In a model nuclear industry exhaust gas, ZUL-530 exhibits a top-class Xe dynamic capacity (28.8 mmol kg) for trace Xe, which proves it is one of the best candidates for Xe/Kr separation.
由于Xe和Kr形状相同且物理化学性质相似，对它们进行吸附分离是一个具有工业前景但颇具挑战性的过程。在此，我们展示了一种策略，即通过合理设计阴离子功能超微孔材料（FUMs）的连接体来精细调节孔道化学性质和结构，从而创建独特的阶梯状通道，其中包含密集的极性纳米陷阱，以产生更大的有效孔空间，并实现Xe的密集堆积。制备了一种新型水解稳定的FUM（ZUL-530），首次在金属有机框架（MOF）中（基于实验数据）实现了Xe在大气条件下的堆积密度超过液态Xe密度，从而兼具出色的Xe吸附量（在0.2 bar下为2.55 mmol g）和高IAST选择性（20.5）。GCMC和DFT-D计算揭示了阶梯状陷阱在Xe密集堆积中的关键作用。突破实验表明，对于Xe/Kr（20:80）混合物，高纯度Kr（6.70 mmol g）和Xe（1.78 mmol g）均具有显著的生产率。在模拟核工业废气中，ZUL-530对痕量Xe表现出一流的Xe动态容量（28.8 mmol kg），这证明它是Xe/Kr分离的最佳候选材料之一。
