Fabrication of Crystalline Microporous Membrane from 2D MOF Nanosheets for Gas Separation

Metal‐organic frameworks (MOFs)‐based membranes have shown great potentials as applications in gas separation. In this work, a uniform membrane based on 2D MOF Ni 3 (HITP) 2 (HITP=2,3,6,7,10,11‐hexaaminotriphenylene) was fabricated on ordered macroporous AAO via the filtration method. To fabricate the membrane, we obtained the Ni 3 (HITP) 2 nanosheets as building blocks via a soft‐physical exfoliation method successfully that were confirmed by AFM and TEM. We also studied the H 2 , CO 2 and N 2 adsorption isotherms of Ni 3 (HITP) 2 powder at room temperature, which shows Ni 3 (HITP) 2 has high heats of adsorption for CO 2 and high selectivity of CO 2 over N 2 . Gas permeation tests indicate that the Ni 3 (HITP) 2 membrane shows high permeance and selectivity of CO 2 over N 2 , as well as good selectivity of H 2 over N 2 . The ideal separation factors of CO 2 /N 2 and H 2 /N 2 from sing‐gas permeances are 13.6 and 7.8 respectively, with CO 2 permeance of 3.15×10 −6  mol⋅m −2 ⋅s −1 ⋅Pa −1 . The membrane also showed good stability, durability and reproducibility, which are of potential interest for practical applications in the CO 2 separations.