Unexpected Molecular Sieving Properties of Zeolitic Imidazolate Framework-8
Citations Over TimeTop 1% of 2012 papers
Abstract
We studied molecular sieving properties of zeolitic imidazolate framework-8 (ZIF-8) by estimating the thermodynamically corrected diffusivities of probe molecules at 35 °C. From helium (2.6 Å) to iso-C4H10 (5.0 Å), the corrected diffusivity drops 14 orders of magnitude. Our results further suggest that the effective aperture size of ZIF-8 for molecular sieving is in the range of 4.0 to 4.2 Å, which is significantly larger than the XRD-derived value (3.4 Å) and between the well-known aperture size of zeolite 4A (3.8 Å) and 5A (4.3 Å). Interestingly, because of aperture flexibility, the studied C4 hydrocarbon molecules that are larger than this effective aperture size still adsorb in the micropores of ZIF-8 with kinetic selectivities for iso-C4H8/iso-C4H10 of 180 and n-C4H10/iso-C4H10 of 2.5 × 10(6). These unexpected molecular sieving properties open up new opportunities for ZIF materials for separations that cannot be economically achieved by traditional microporous adsorbents such as synthetic zeolites.
Related Papers
- → Unusual microporous polycatenane-like metal–organic frameworks for the luminescent sensing of Ln3+ cations and rapid adsorption of iodine(2012)98 cited
- → Xe adsorption and separation properties of a series of microporous metal–organic frameworks (MOFs) with V-shaped linkers(2017)46 cited
- → Generation of Hierarchical Porosity in Metal–Organic Frameworks by the Modulation of Cation Valence(2019)15 cited
- → Possibilities of Microporous and Hierarchical MFI Zeolites in the Synthesis of Nitrogen Heterocyclic Compounds(2022)4 cited
- Synthesis, Postmodification, Metalation, and Gas Adsorption in Chemically Stable Metal Organic Frameworks and Zeolitic Imidazolate Frameworks.(2012)