Open AccessCombining In Situ Techniques (XRD, IR, and 13C NMR) and Gas Adsorption Measurements Reveals CO2-Induced Structural Transitions and High CO2/CH4 Selectivity for a Flexible Metal–Organic Framework JUK-8
Author(s) -
Kornel Roztocki,
Marcus Rauche,
Volodymyr Bon,
Stefan Kaskel,
Eike Brunner,
Dariusz Matoga
Publication year - 2021
Publication title -
acs applied materials and interfaces
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.535
H-Index - 228
eISSN - 1944-8252
pISSN - 1944-8244
DOI - 10.1021/acsami.1c07268
Subject(s) - materials science , adsorption , in situ , single crystal , metal organic framework , crystallography , carbon fibers , carbon dioxide , selectivity , x ray crystallography , diffraction , chemistry , analytical chemistry (journal) , organic chemistry , physics , composite number , optics , composite material , catalysis
Flexible metal-organic frameworks (MOFs) are promising materials in gas-related technologies. Adjusting the material to processes requires understanding of the flexibility mechanism and its influence on the adsorption properties. Herein, we present the mechanistic understanding of CO 2 -induced pore-opening transitions of the water-stable MOF JUK-8 ([Zn(oba)(pip)] n , oba 2- = 4,4'-oxybis(benzenedicarboxylate), pip = 4-pyridyl-functionalized benzene-1,3-dicarbohydrazide) as well as its potential applicability in gas purification. Detailed insights into the global structural transformation and subtle local MOF-adsorbate interactions are obtained by three in situ techniques (XRD, IR, and 13 CO 2 -NMR). These results are further supported by single-crystal X-ray diffraction (SC-XRD) analysis of the solvated and guest-free phases. High selectivity toward carbon dioxide derived from the single-gas adsorption experiments of CO 2 (195 and 298 K), Ar (84 K), O 2 (90 K) , N 2 (77 K), and CH 4 (298 K) is confirmed by high-pressure coadsorption experiments of the CO 2 /CH 4 (75:25 v/v) mixture at different temperatures (288, 293, and 298 K) and in situ NMR studies of the coadsorption of 13 CO 2 / 13 CH 4 (50:50 v/v; 195 K).