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Ultra‐Tuning of the Aperture Size in Stiffened ZIF‐8_Cm Frameworks with Mixed‐Linker Strategy for Enhanced CO 2 /CH 4 Separation
Author(s) -
Hou Qianqian,
Wu Ying,
Zhou Sheng,
Wei Yanying,
Caro Jürgen,
Wang Haihui
Publication year - 2019
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201811638
Subject(s) - membrane , linker , materials science , selectivity , aperture (computer memory) , chemical engineering , nanotechnology , chemistry , organic chemistry , computer science , catalysis , biochemistry , physics , acoustics , engineering , operating system
ZIF‐8 membrane has the potential for CO 2 /CH 4 separation based on size exclusion. But if traditionally prepared by solvothermal methods, it shows only negligible selectivity due to the linker mobility. Here, ≈500 nm‐thin hybrid ZIF‐7 x ‐8 membranes with suppressed linker mobility and narrowed window aperture are prepared by a fast current‐driven synthesis (FCDS) within 20 min. The in situ electric field during FCDS allows the formation of stiffened ZIF‐8_Cm as parent skeleton and the mixed‐linker strategy is applied to narrow the aperture size simultaneously. The ZIF‐7 22 ‐8 membrane shows significantly sharpened molecular sieving for CO 2 /CH 4 with a separation factor above 25, which soared tenfold compared with other unmodified ZIF‐8 membranes. Additionally, the membrane shows exceptional separation performance for H 2 /CH 4 and CO 2 /N 2 , with separation factors of 71 and 20, respectively. After 180 h temperature swing operation, it still maintains the excellent separation performance.