Wang Qingju, Ke Tian, Yang Lifeng, Zhang Zhaoqiang, Cui Xili, Bao Zongbi, Ren Qilong, Yang Qiwei, Xing Huabin
Key Laboratory of Biomass Chemical Engineering of ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China.
Angew Chem Int Ed Engl. 2020 Feb 24;59(9):3423-3428. doi: 10.1002/anie.201913245. Epub 2020 Jan 9.
The separation of xenon/krypton (Xe/Kr) mixture is of great importance to industry, but the available porous materials allow the adsorption of both, Xe and Kr only with limited selectivity. Herein we report an anion-pillared ultramicroporous material NbOFFIVE-2-Cu-i (ZU-62) with finely tuned pore aperture size and structure flexibility, which for the first time enables an inverse size-sieving effect in separation along with record Xe/Kr selectivity and ultrahigh Xe capacity. Evidenced by single-crystal X-ray diffraction, the rotation of anions and pyridine rings upon contact of larger-size Xe atoms adapts cavities to the shape/size of Xe and allows strong host-Xe interaction, while the smaller-size Kr is excluded. Breakthrough experiments confirmed that ZU-62 has a real practical potential for producing high-purity Kr and Xe from air-separation byproducts, showing record Kr productivity (206 mL g ) and Xe productivity (42 mL g , in desorption) as well as good recyclability.
氙/氪（Xe/Kr）混合物的分离对工业具有重要意义，但现有的多孔材料对Xe和Kr的吸附选择性有限。在此，我们报道了一种阴离子柱撑超微孔材料NbOFFIVE-2-Cu-i（ZU-62），其具有精细调控的孔径大小和结构灵活性，首次在分离中实现了反尺寸筛分效应，同时具有创纪录的Xe/Kr选择性和超高Xe容量。单晶X射线衍射表明，较大尺寸的Xe原子接触时阴离子和吡啶环的旋转使孔穴适应Xe的形状/大小，并允许主体与Xe之间产生强相互作用，而较小尺寸的Kr则被排除在外。突破实验证实，ZU-62在从空气分离副产物中生产高纯度Kr和Xe方面具有实际应用潜力，显示出创纪录的Kr生产率（206 mL g）和Xe生产率（42 mL g，解吸时）以及良好的可回收性。
