Zeolitic imidazolate frameworks (ZIFs) are promising for gas separation membrane, but their molecular cut-off differs from that expected from its intrinsic aperture structure because of their flexibility. Herein, we introduced graphene nanoribbons (GNRs) to rigidify the ZIF framework. Because the sp2 edge of the GNRs induces strong anchoring effects, the modified layer can be rigidified. Particularly, when the GNRs were embedded and distributed in the ZIF-8 layer, an intrinsic aperture size of 3.4 Å was observed, resulting in high H2/CO2 separation (H2 permeance: 5.2×10−6 mol/m2 Pa s, ideal selectivity: 142). The performance surpasses the upper bound of polycrystalline MOF membrane performance. In addition, the membrane can be applied to blue H2 production, as demonstrated with a simulated steam reformed gas containing H2/CO2/CH4. The separation performance was retained in the presence of water. The fundamentals of the molecular transport through the rigid ZIF-8 framework were revealed using molecular dynamics simulations.
|Journal||Angewandte Chemie - International Edition|
|Publication status||Published - 2022 Dec 5|
Bibliographical noteFunding Information:
This study was supported by a National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIT) (NRF‐2020R1C1C1003289), and by the Technology Innovation Program (20013621, Center for Super Critical Material Industrial Technology), funded by the Ministry of Trade, Industry and Energy (MOTIE, Korea).
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