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

Published

May 16, 2018

Author(s)

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

Abstract

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.

Citation

ACS Applied Materials and Interfaces

Volume

10

Issue

19

Pub Type

Journals

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Keywords

Metal-organic frameworks, Gas separation, CO2 capture

Citation

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 CO₂ Combined with Ultrahigh Uptake Capacity, ACS Applied Materials and Interfaces, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=925847 (Accessed November 12, 2025)