Title: Molecular Simulation of Capture of Sulfur-Containing Gases by Porous Aromatic Frameworks

Abstract

The adsorption of pure SO2 and H2S and their selective adsorption from various gas mixtures by porous aromatic frameworks (PAFs) are investigated using grand canonical Monte Carlo (GCMC) simulations and first-principles density functional theory calculations. The influence of functional groups including -CH₃, -CN, -COOH, -COOCH₃, -OH, -OCH₃, -NH₂, and -NO₂ on the adsorption of pure SO₂ and H₂S as well as selective capture of SO₂ and H₂S from SO₂/N₂, SO₂/CO₂, H₂S/CO₂, and H₂S/CH₄ mixtures is explored. Our calculations indicate that PAFs exhibit high loadings for pure SO₂ and H₂S gas adsorption at 298 K up to 40 bar compare to other gases such as CH₄ and CO₂. Additional functional groups enhance gas uptake at low pressures because of stronger interaction with the gas molecules while reducing gas uptake at high pressures because of a decrease in pore volume. The contributions of electrostatic interactions to gas adsorption loadings are analyzed in GCMC simulations. Ideal adsorbed solution theory calculations generally overestimate SO₂ and H₂S adsorption selectivity in gas mixtures but qualitatively predict the trends seen in GCMC simulations for these systems. The GCMC simulations further show that the inclusion of any of the functional groups we considered increases the selectivity of SO₂/N₂,more » SO₂/CO₂, H₂S/CO₂, and H₂S/CH₄ relative to unfunctionalized materials. Electron-withdrawing groups such as -CN, -COOH, -COOCH₃, and -NO₂ are more effective at enhancing adsorption selectivity in this work. Finally, the highest selectivity in the PAFs functionalized by these groups is predicted at the lowest temperature we considered (273 K), whereas it occurs at 298 K for PAFs with other functional groups.« less

Authors:

Zhang, Difan  ^[1];

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• Search DOE PAGES for ORCID "0000-0001-7530-2378"

Jing, Xiaofei ^[2]; Sholl, David S.  ^[3];

• Search DOE PAGES for author "Sholl, David S."
• Search DOE PAGES for ORCID "0000-0002-2771-9168"

Sinnott, Susan B. ^[4]

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+ Show Author Affiliations

1. Univ. of Florida, Gainesville, FL (United States). Dept. of Materials Science and Engineering; Pennsylvania State Univ., University Park, PA (United States). Dept. of Materials Science and Engineering
2. Georgia Inst. of Technology, Atlanta, GA (United States). School of Chemical and Biomolecular Engineering; Northeast Normal Univ., Changchun (China). Dept. of Chemistry, Key Lab. of Polyoxometalate Science of Ministry of Education
3. Georgia Inst. of Technology, Atlanta, GA (United States). School of Chemical and Biomolecular Engineering
4. Pennsylvania State Univ., University Park, PA (United States). Dept. of Materials Science and Engineering

Publication Date:

Fri Jul 27 00:00:00 EDT 2018

Research Org.:

Energy Frontier Research Centers (EFRC) (United States). Center for Understanding and Control of Acid Gas-induced Evolution of Materials for Energy (UNCAGE-ME)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES)

OSTI Identifier:

1470676

Grant/Contract Number:  

SC0012577

Resource Type:

Accepted Manuscript

Journal Name:

Journal of Physical Chemistry. C

Additional Journal Information:

Journal Volume: 122; Journal Issue: 32; Related Information: UNCAGE-ME partners with Georgia Institute of Technology (lead); Lehigh University; Oak Ridge National Laboratory; University of Alabama; University of Florida; University of Wisconsin; Washington University in St. Louis; Journal ID: ISSN 1932-7447

Publisher:

American Chemical Society

Country of Publication:

United States

Language:

English

Subject:

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; catalysis (heterogeneous); defects; membrane; carbon capture; materials and chemistry by design; synthesis (novel materials); synthesis (self-assembly); synthesis (scalable processing)