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Mesopore engineering of ZIF-8 by [Bmim][Tf2N] positioning into nanocage for enhanced CO2 capture.
- Source :
-
Chemical Engineering Science . Oct2023, Vol. 280, pN.PAG-N.PAG. 1p. - Publication Year :
- 2023
-
Abstract
- • In-situ position of ILs into cages of ZIF-8 was proposed to tune cage size. • CO 2 -philic cages constructed by ILs improve CO 2 adsorption. • Molecular simulation reveals increased CO 2 adsorption by increasing ILs in cages. • CO 2 /N 2 selectivity of MMMs is increased due to pore screening and CO 2 adsorption. The regulation on cage size and CO 2 -philic environment of metal–organic frameworks (MOFs) is essential to improve CO 2 capture. In this work, [Bmim][Tf 2 N] was proposed to position into cages of ZIF-8 to achieve the selective permeation of CO 2 by pore screening and CO 2 adsorption. [Bmim][Tf 2 N] was introduced into cages of ZIF-8 by "adsorption-infiltration" strategy. Due to the strong interaction between [Tf 2 N]− and ZIF-8, the cages present a CO 2 -philic environment, which preferentially attracts CO 2 to enter these cages, ensuring the dissolution selectivity of CO 2. Besides, the proper cage size tuned by [Bmim][Tf 2 N] provides CO 2 with a faster transport channel due to its smaller average kinetic diameter than N 2 , guaranteeing the diffusion selectivity of CO 2. Consequently, the CO 2 separation in [Bmim][Tf 2 N]@ZIF-8/Pebax MMMs is intensified. With increasing the [Bmim][Tf 2 N] content in cages of ZIF-8, the pore volume by BET results decreases and the CO 2 adsorption from molecular simulation increases. In response, the CO 2 /N 2 selectivity of [Bmim][Tf 2 N]@ZIF-8/Pebax MMMs is enhanced constantly. Meanwhile, the CO 2 permeability is declined due to the narrowed cage size. All of these results demonstrate the significance of pore screening and CO 2 adsorption induced by [Bmim][Tf 2 N]. Specifically, [Bmim][Tf 2 N] 8 @ZIF-8/Pebax MMM at filler loading of 15 wt% exhibits the CO 2 permeability of 108.3 Barrer and the CO 2 /N 2 selectivity of 86.7, exceeding the 2008 Robeson upper bound. Especially the CO 2 /N 2 selectivity locates at a higher level than those of most reported works, indicating that appropriate tuning of the physicochemical properties within the nanocages of MOFs is significative to improve CO 2 capture. [ABSTRACT FROM AUTHOR]
- Subjects :
- *CARBON sequestration
*CARBON dioxide
*DIFFUSION
*METAL-organic frameworks
Subjects
Details
- Language :
- English
- ISSN :
- 00092509
- Volume :
- 280
- Database :
- Academic Search Index
- Journal :
- Chemical Engineering Science
- Publication Type :
- Academic Journal
- Accession number :
- 169968677
- Full Text :
- https://doi.org/10.1016/j.ces.2023.118998