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Controlling Pore Shape and Size of Interpenetrated Anion-Pillared Ultramicroporous Materials Enables Molecular Sieving of CO2 Combined with Ultrahigh Uptake Capacity



Mengdie Jiang, Bin Li, Xili Cui, Qiwei Yang, Zongbi Bao, Yiwen Yang, Hui Wu, Wei Zhou, Banglin Chen, Huabin Xing


The separation of carbon dioxide (CO2) from hydrocarbons is a critical process for the production of clean energy and high-purity chemicals. Adsorption based on molecular sieving is an energy-saving separation process; however most of molecular sieves with narrow and straight pore channels exhibit low CO2 uptake capacity. Here we report that a two-fold interpenetrated copper coordination network with consecutive pocket-like pore structure, namely, SIFSIX-14-Cu-i (SIFISX=hexafluorosilicate, 14=4,4'-azopyridine, i=interpenetrated) is a remarkable CO2/CH4 molecular-sieving adsorbent which completely blocks the larger CH4 molecule with unprecedented selectivity, while has excellent CO2 uptake (172.7 cm3/cm3) under the ambient condition. The exceptional separation performance of SIFSIX-14-Cu-i is attributed to its unique pore shape and functional pore surface, which combine a contracted pore window (3.4angstrom}) and a relatively large pore cavity decorated with high-density of inorganic anions. Dispersion-corrected density-functional theory (DFT-D) calculation and neutron powder diffraction were performed to understand the CO2 binding sites. The practical feasibility of SIFSIX-14-Cu-i for CO2/CH4 mixtures separation was validated by experimental breakthrough tests. This study not only demonstrates the great potential of SIFSIX-14-Cu-i for CO2 separation, but also provides important clues for other gas separations.
ACS Applied Materials and Interfaces


Metal-organic frameworks, Gas separation, CO2 capture


Jiang, M. , Li, B. , Cui, X. , Yang, Q. , Bao, Z. , Yang, Y. , Wu, H. , Zhou, W. , Chen, B. and Xing, H. (2018), Controlling Pore Shape and Size of Interpenetrated Anion-Pillared Ultramicroporous Materials Enables Molecular Sieving of CO<sub>2</sub> Combined with Ultrahigh Uptake Capacity, ACS Applied Materials and Interfaces, [online], (Accessed April 23, 2024)
Created May 15, 2018, Updated October 12, 2021