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Separation of Xe from Kr with Record Selectivity and Productivity in Anion‐Pillared Ultramicroporous Materials by Inverse Size‐Sieving
Author(s) -
Wang Qingju,
Ke Tian,
Yang Lifeng,
Zhang Zhaoqiang,
Cui Xili,
Bao Zongbi,
Ren Qilong,
Yang Qiwei,
Xing Huabin
Publication year - 2020
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201913245
Subject(s) - krypton , selectivity , xenon , chemistry , ion , adsorption , sorption , analytical chemistry (journal) , chromatography , organic chemistry , catalysis
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 −1 ) and Xe productivity (42 mL g −1 , in desorption) as well as good recyclability.