Restricting Lattice Flexibility in Polycrystalline Metal-Organic Framework Membranes for Carbon Capture
© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
| Veröffentlicht in: | Advanced materials (Deerfield Beach, Fla.). - 1998. - 31(2019), 28 vom: 22. Juli, Seite e1900855 |
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| Weitere Verfasser: | , , , , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2019
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| Zugriff auf das übergeordnete Werk: | Advanced materials (Deerfield Beach, Fla.) |
| Schlagworte: | Journal Article CO2 capture defect engineering lattice flexibility metal-organic frameworks molecular sieving |
| Zusammenfassung: | © 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Although polycrystalline metal-organic framework (MOF) membranes offer several advantages over other nanoporous membranes, thus far they have not yielded good CO2 separation performance, crucial for energy-efficient carbon capture. ZIF-8, one of the most popular MOFs, has a crystallographically determined pore aperture of 0.34 nm, ideal for CO2 /N2 and CO2 /CH4 separation; however, its flexible lattice restricts the corresponding separation selectivities to below 5. A novel postsynthetic rapid heat treatment (RHT), implemented in a few seconds at 360 °C, which drastically improves the carbon capture performance of the ZIF-8 membranes, is reported. Lattice stiffening is confirmed by the appearance of a temperature-activated transport, attributed to a stronger interaction of gas molecules with the pore aperture, with activation energy increasing with the molecular size (CH4 > CO2 > H2 ). Unprecedented CO2 /CH4 , CO2 /N2 , and H2 /CH4 selectivities exceeding 30, 30, and 175, respectively, and complete blockage of C3 H6 , are achieved. Spectroscopic and X-ray diffraction studies confirm that while the coordination environment and crystallinity are unaffected, lattice distortion and strain are incorporated in the ZIF-8 lattice, increasing the lattice stiffness. Overall, RHT treatment is a facile and versatile technique that can vastly improve the gas-separation performance of the MOF membranes |
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| Beschreibung: | Date Revised 01.10.2020 published: Print-Electronic Citation Status PubMed-not-MEDLINE |
| ISSN: | 1521-4095 |
| DOI: | 10.1002/adma.201900855 |