Cooperative CO2 adsorption mechanism in a perfluorinated CeIV-based metal organic framework
| Autor: | Cavallo, Margherita, Atzori, Cesare, Signorile, Matteo, Costantino, Ferdinando, Venturi, Diletta Morelli, Koutsianos, Athanasios, Lomachenko, Kirill A., Calucci, Lucia, Martini, Francesca, Giovanelli, Andrea, Geppi, Marco, Crocellà, Valentina, Taddei, Marco |
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| Rok vydání: | 2023 |
| Předmět: | |
| Zdroj: | Journal of materials chemistry / A 11(11), 5568-5583 (2023). doi:10.1039/D2TA09746J |
| ISSN: | 2050-7496 2050-7488 |
| DOI: | 10.1039/d2ta09746j |
| Popis: | Journal of materials chemistry / A 11(11), 5568 - 5583 (2023). doi:10.1039/D2TA09746J Adsorbents able to uptake large amounts of gases within a narrow range of pressure, i.e., phase-change adsorbents, are emerging as highly interesting systems to achieve excellent gas separation performances with little energy input for regeneration. A recently discovered phase-change metal–organic framework (MOF) adsorbent is F4_MIL-140A(Ce), based on Ce$^{IV}$ and tetrafluoroterephthalate. This MOF displays a non-hysteretic step-shaped CO$_2$ adsorption isotherm, reaching saturation in conditions of temperature and pressure compatible with real life application in post-combustion carbon capture, biogas upgrading and acetylene purification. Such peculiar behaviour is responsible for the exceptional CO$_2$/N$_2$ selectivity and reverse CO$_2$/C$_2$H$_2$ selectivity of F4_MIL-140A(Ce). Here, we combine data obtained from a wide pool of characterisation techniques – namely gas sorption analysis, in situ infrared spectroscopy, in situ powder X-ray diffraction, in situ X-ray absorption spectroscopy, multinuclear solid state nuclear magnetic resonance spectroscopy and adsorption microcalorimetry – with periodic density functional theory simulations to provide evidence for the existence of a unique cooperative CO$_2$ adsorption mechanism in F4_MIL-140A(Ce). Such mechanism involves the concerted rotation of perfluorinated aromatic rings when a threshold partial pressure of CO$_2$ is reached, opening the gate towards an adsorption site where CO$_2$ interacts with both open metal sites and the fluorine atoms of the linker. Published by RSC, London [u.a.] |
| Databáze: | OpenAIRE |
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