TY - JOUR

T1 - Enhanced Adsorption Selectivity of Carbon Dioxide and Ethane on Porous Metal–Organic Framework Functionalized by a Sulfur-Rich Heterocycle

AU - Dubskikh, Vadim A.

AU - Kovalenko, Konstantin A.

AU - Nizovtsev, Anton S.

AU - Lysova, Anna A.

AU - Samsonenko, Denis G.

AU - Dybtsev, Danil N.

AU - Fedin, Vladimir P.

N1 - Funding Information: The research was supported by Russian Science Foundation, project № 18-13-00203, https://rscf.ru/project/18-13-00203. The analytical services and quantum chemical calculations were supported by the Ministry of Science and Higher Education of the Russian Federation (Projects 121031700321-3 and 121031700313-8). Publisher Copyright: © 2022 by the authors.

PY - 2022/12

Y1 - 2022/12

N2 - Porous metal–organic framework [Zn2(ttdc)2(bpy)] (1) based on thieno [3,2-b]thiophenedicarboxylate (ttdc) was synthesized and characterized. The structure contains intersected zig-zag channels with an average aperture of 4 × 6 Å and a 49% (v/v) guest-accessible pore volume. Gas adsorption studies confirmed the microporous nature of 1 with a specific surface area (BET model) of 952 m2·g–1 and a pore volume of 0.37 cm3·g–1. Extensive CO2, N2, O2, CO, CH4, C2H2, C2H4 and C2H6 gas adsorption experiments at 273 K and 298 K were carried out, which revealed the great adsorption selectivity of C2H6 over CH4 (IAST selectivity factor 14.8 at 298 K). The sulfur-rich ligands and double framework interpenetration in 1 result in a dense decoration of the inner surface by thiophene heterocyclic moieties, which are known to be effective secondary adsorption sites for carbon dioxide. As a result, remarkable CO2 adsorption selectivities were obtained for CO2/CH4 (11.7) and CO2/N2 (27.2 for CO2:N2 = 1:1, 56.4 for CO2:N2 = 15:85 gas mixtures). The computational DFT calculations revealed the decisive role of the sulfur-containing heterocycle moieties in the adsorption of CO2 and C2H6. High CO2 adsorption selectivity values and a relatively low isosteric heat of CO2 adsorption (31.4 kJ·mol–1) make the porous material 1 a promising candidate for practical separation of biogas as well as for CO2 sequestration from flue gas or natural gas.

AB - Porous metal–organic framework [Zn2(ttdc)2(bpy)] (1) based on thieno [3,2-b]thiophenedicarboxylate (ttdc) was synthesized and characterized. The structure contains intersected zig-zag channels with an average aperture of 4 × 6 Å and a 49% (v/v) guest-accessible pore volume. Gas adsorption studies confirmed the microporous nature of 1 with a specific surface area (BET model) of 952 m2·g–1 and a pore volume of 0.37 cm3·g–1. Extensive CO2, N2, O2, CO, CH4, C2H2, C2H4 and C2H6 gas adsorption experiments at 273 K and 298 K were carried out, which revealed the great adsorption selectivity of C2H6 over CH4 (IAST selectivity factor 14.8 at 298 K). The sulfur-rich ligands and double framework interpenetration in 1 result in a dense decoration of the inner surface by thiophene heterocyclic moieties, which are known to be effective secondary adsorption sites for carbon dioxide. As a result, remarkable CO2 adsorption selectivities were obtained for CO2/CH4 (11.7) and CO2/N2 (27.2 for CO2:N2 = 1:1, 56.4 for CO2:N2 = 15:85 gas mixtures). The computational DFT calculations revealed the decisive role of the sulfur-containing heterocycle moieties in the adsorption of CO2 and C2H6. High CO2 adsorption selectivity values and a relatively low isosteric heat of CO2 adsorption (31.4 kJ·mol–1) make the porous material 1 a promising candidate for practical separation of biogas as well as for CO2 sequestration from flue gas or natural gas.

KW - adsorption selectivity

KW - benzene and cyclohexane separation

KW - gas adsorption

KW - metal–organic framework

KW - thieno[3,2-b]thiophenedicarboxylic acid

UR - http://www.scopus.com/inward/record.url?scp=85143697038&partnerID=8YFLogxK

UR - https://www.mendeley.com/catalogue/5b5d58cd-0a28-37d6-ba93-172729c7fcd5/

U2 - 10.3390/nano12234281

DO - 10.3390/nano12234281

M3 - Article

C2 - 36500905

AN - SCOPUS:85143697038

VL - 12

JO - Nanomaterials

JF - Nanomaterials

SN - 2079-4991

IS - 23

M1 - 4281

ER -