Revealing the Transient Concentration of CO2 in a Mixed-Matrix Membrane by IR Microimaging and Molecular Modeling

Seungtaik Hwang; Rocio Semino; Beatriz Seoane; Marufa Zahan; Christian Chmelik; Rustem Valiullin; Marko Bertmer; Jürgen Haase; Freek Kapteijn; Jorge Gascon; Guillaume Maurin; Jörg Kärger

doi:10.1002/anie.201713160

Revealing the Transient Concentration of CO₂ in a Mixed-Matrix Membrane by IR Microimaging and Molecular Modeling

Angew Chem Int Ed Engl. 2018 Apr 23;57(18):5156-5160. doi: 10.1002/anie.201713160. Epub 2018 Mar 25.

Authors

Seungtaik Hwang¹, Rocio Semino^{2

3}, Beatriz Seoane^{4

5}, Marufa Zahan¹, Christian Chmelik¹, Rustem Valiullin¹, Marko Bertmer¹, Jürgen Haase¹, Freek Kapteijn⁵, Jorge Gascon^{5

6}, Guillaume Maurin², Jörg Kärger¹

Affiliations

¹ Faculty of Physics and Earth Sciences, University of Leipzig, Linnéstrasse 5, 04103, Leipzig, Germany.
² Institut Charles Gerhardt Montpellier, Université de Montpellier, Place Eugène Bataillon, 34095, Montpellier Cedex 5, France.
³ Institute of Materials, École Polytechnique Fédérale de Lausanne, Route Cantonale, 1015, Lausanne, Switzerland.
⁴ Debye Institute for Nanomaterials Science, Utrecht University, Universiteitsweg 99, 3584, CG, Utrecht, The Netherlands.
⁵ Catalysis Engineering, ChemE Department, Delft University of Technology, Van der Maasweg 9, 2629, HZ, Delft, The Netherlands.
⁶ Advanced Catalytic Materials, KAUST Catalysis Center, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia.

PMID: 29465815
DOI: 10.1002/anie.201713160

Abstract

Through IR microimaging the spatially and temporally resolved development of the CO₂ concentration in a ZIF-8@6FDA-DAM mixed matrix membrane (MMM) was visualized during transient adsorption. By recording the evolution of the CO₂ concentration, it is observed that the CO₂ molecules propagate from the ZIF-8 filler, which acts as a transport "highway", towards the surrounding polymer. A high-CO₂ -concentration layer is formed at the MOF/polymer interface, which becomes more pronounced at higher CO₂ gas pressures. A microscopic explanation of the origins of this phenomenon is suggested by means of molecular modeling. By applying a computational methodology combining quantum and force-field based calculations, the formation of microvoids at the MOF/polymer interface is predicted. Grand canonical Monte Carlo simulations further demonstrate that CO₂ tends to preferentially reside in these microvoids, which is expected to facilitate CO₂ accumulation at the interface.

Keywords: IR spectroscopy; adsorption; interfaces; mixed-matrix membranes; molecular modeling.

Publication types

Research Support, Non-U.S. Gov't