Ultrahigh and Selective SO2 Uptake in Inorganic Anion-Pillared Hybrid Porous Materials

Published

July 21, 2017

Author(s)

Xili Cui, Qiwei Yang, Lifeng Yang, Rajamani Krishna, Zhiguo Zhang, Zongbi Bao, Hui Wu, Zongbi Ren, Wei Zhou, Banglin Chen, Huabin Xing

Abstract

The efficient capture of SO₂ is of great significance in gas purification processes including the flue gas desulfurization (FGD) and natural gas purification, but the design of porous materials with high adsorption capacity and selectivity of SO₂ remains very challenging. Herein, we report the selective recognition and dense packing of SO₂ clusters through multiple synergistic host-guest and guest-guest interactions by controlling the pore chemistry and size in inorganic anion (SiF₆^2-, SIFSIX) pillared metal-organic frameworks. The binding sites of anions and aromatic rings in SIFSIX materials grasp every atom of SO₂ firmly via S^δ+···F^δ- electrostatic interaction and O^δ-···H^δ+ dipole-dipole interactions, while the guest-guest interactions between SO₂ molecules further promote the gas trapping within pore space, which is elucidated by the first-principles density functional theory calculations. These interactions afford new benchmarks for the highly efficient removal of SO₂ from other gases, even if at a very low SO₂ concentration. Exceptionally high SO₂ capacity of 11.01 mmol/g was achieved at atmosphere pressure by SIFSIX-1-Cu, and unprecedented low-pressure SO₂ capacity was obtained in SIFSIX-2-Cu-i (4.16 mmol/g SO₂ at 0.01 bar and 2.31 mmol/g at 0.002 bar). More importantly, record SO₂/CO₂ selectivity (8689) and excellent SO₂/N₂ selectivity (12853145) were also achieved. Experimental breakthrough curves further demonstrated the excellent performance of these hybrid porous materials in removing low-concentration SO₂.

Citation

Advanced Materials

Volume

29

Issue

28

Pub Type

Journals

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Keywords

SO2 capture, gas purification, metal-organic frameworks

Citation

Cui, X. , Yang, Q. , Yang, L. , Krishna, R. , Zhang, Z. , Bao, Z. , Wu, H. , Ren, Z. , Zhou, W. , Chen, B. and Xing, H. (2017), Ultrahigh and Selective SO₂ Uptake in Inorganic Anion-Pillared Hybrid Porous Materials, Advanced Materials, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=922452 (Accessed December 9, 2024)