Title
The Influence of UiO-66 Metal–Organic Framework Structural Defects on Adsorption and Separation of Hexane Isomers
Author
Sławek, Andrzej (AGH University of Science and Technology)
Jajko, Gabriela (Jagiellonian University)
Ogorzały, Karolina (Jagiellonian University)
Dubbeldam, David (Universiteit van Amsterdam)
Vlugt, T.J.H. (TU Delft Engineering Thermodynamics) 
Makowski, Wacław (Jagiellonian University)
Date
2022
Abstract
In this work, adsorption properties of the UiO-66 metal–organic framework were investigated, with particular emphasis on the influence of structural defects. A series of UiO-66 samples were synthesized and characterized using a wide range of experimental techniques. Type I adsorption isotherms for low-temperature adsorption of N2 and Ar showed that micropore volume and specific surface area significantly increase with the number of defects. Adsorption of hexane isomers in UiO-66 was studied by means of quasi-equilibrated temperature-programmed desorption and adsorption (QE-TPDA) experimental and Monte Carlo simulation techniques. QE-TPDA profiles revealed that only defect-free UiO-66 exhibits distinct two adsorption states. This technique also yielded high-quality adsorption isobars that were successfully recreated using Grand-Canonical Monte Carlo molecular simulations, which, however, required refinement of the existing force fields. The calculations demonstrated the detailed mechanism of adsorption and separation of hexane isomers in the UiO-66 structure. The preferred tetrahedral cages provide suitable voids for bulky molecules, which is the reason for unusual “reverse” selectivity of UiO-66 towards di-branched alkanes. Interconnection of the tetrahedral cavities due to missing organic linkers greatly reduces the selectivity of the defected material.
Subject
adsorption
hydrocarbons
linker vacancies
metal–organic framework
separation
To reference this document use:
http://resolver.tudelft.nl/uuid:9eb88470-6fee-4aa9-863f-dac9809df985
DOI
https://doi.org/10.1002/chem.202200030
Embargo date
2023-07-01
ISSN
0947-6539
Source
Chemistry: A European Journal, 28 (29)
Bibliographical note
Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.
Part of collection
Institutional Repository
Document type
journal article
Rights
© 2022 Andrzej Sławek, Gabriela Jajko, Karolina Ogorzały, David Dubbeldam, T.J.H. Vlugt, Wacław Makowski