title: Confinement of Ionic Liquids in Nanocages: Tailoring the Molecular Sieving Properties of ZIF-8 for Membrane-Based CO2 Capture.
abstract: Fine-tuning of effective pore size of microporous materials is necessary to achieve precise molecular sieving properties. Herein, we demonstrate that room temperature ionic liquids can be used as cavity occupants for modification of the microenvironment of MOF nanocages. Targeting CO2 capture applications, we tailored the effective cage size of ZIF-8 to be between CO2 and N2 by confining an imidazolium-based ionic liquid [bmim][Tf2 N] into ZIF-8's SOD cages by in-situ ionothermal synthesis. Mixed matrix membranes derived from ionic liquid-modified ZIF-8 exhibited remarkable combinations of permeability and selectivity that transcend the upper bound of polymer membranes for CO2 /N2 and CO2 /CH4 separation. We observed an unusual response of the membranes to varying pressure, that is, an increase in the CO2 /CH4 separation factor with pressure, which is highly desirable for practical applications in natural gas upgrading.
authors.affiliation: State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, CAS, 457 Zhongshan Road, Dalian 116023 (China).|University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049 (China).
authors.forename: Yujie
authors.initials: Y
authors.lastname: Ban
authors.affiliation: State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, 15 Beisanhuan East Road, Beijing 100029 (China).
authors.forename: Zhengjie
authors.initials: Z
authors.lastname: Li
authors.affiliation: State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, CAS, 457 Zhongshan Road, Dalian 116023 (China). leeys@dicp.ac.cn.
authors.forename: Yanshuo
authors.initials: Y
authors.lastname: Li
authors.affiliation: State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, CAS, 457 Zhongshan Road, Dalian 116023 (China).|University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049 (China).
authors.forename: Yuan
authors.initials: Y
authors.lastname: Peng
authors.affiliation: State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, CAS, 457 Zhongshan Road, Dalian 116023 (China).|University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049 (China).
authors.forename: Hua
authors.initials: H
authors.lastname: Jin
authors.affiliation: State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, CAS, 457 Zhongshan Road, Dalian 116023 (China).|University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049 (China).
authors.forename: Wenmei
authors.initials: W
authors.lastname: Jiao
authors.affiliation: State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, CAS, 457 Zhongshan Road, Dalian 116023 (China).|University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049 (China).
authors.forename: Ang
authors.initials: A
authors.lastname: Guo
authors.affiliation: State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, CAS, 457 Zhongshan Road, Dalian 116023 (China).|University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049 (China).
authors.forename: Po
authors.initials: P
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, 15 Beisanhuan East Road, Beijing 100029 (China). qyyang@mail.buct.edu.cn.
authors.forename: Qingyuan
authors.initials: Q
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, 15 Beisanhuan East Road, Beijing 100029 (China).
authors.forename: Chongli
authors.initials: C
authors.lastname: Zhong
authors.affiliation: State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, CAS, 457 Zhongshan Road, Dalian 116023 (China). yangws@dicp.ac.cn.
authors.forename: Weishen
authors.initials: W
authors.lastname: Yang
keywords: CO2 capture; ZIF-8; confinement; ionic liquids; molecular sieving