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

• Published in: Nanomaterials (Basel, Switzerland) Vol. 12; no. 23; p. 4281
• Main Authors: Dubskikh, Vadim A, Kovalenko, Konstantin A, Nizovtsev, Anton S, Lysova, Anna A, Samsonenko, Denis G, Dybtsev, Danil N, Fedin, Vladimir P
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 01.12.2022; MDPI
• Subjects: Adsorption; adsorption selectivity; Alternative energy sources; Analysis; benzene and cyclohexane separation; Biogas; Carbon dioxide; Carbon dioxide fixation; Carbon sequestration; Chemical synthesis; Climate change; Computer applications; Crystals; Density functionals; Ethane; Flue gas; gas adsorption; Gas mixtures; Gases; Heterocyclic compounds; Hydrocarbons; Identification and classification; Metal-organic frameworks; metal–organic framework; Methane; Methods; Natural gas; Organometallic compounds; Porous materials; Properties; Selectivity; Structure; Sulfur; Sulfur compounds; Surface chemistry; thieno[3,2-b]thiophenedicarboxylic acid; Russia; gas adsorption; adsorption selectivity; metal–organic framework; benzene and cyclohexane separation; thieno[3,2-b]thiophenedicarboxylic acid
• ISSN: 2079-4991; 2079-4991
• DOI: 10.3390/nano12234281

Porous metal-organic framework [Zn (ttdc) (bpy)] ( ) 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% ( ) guest-accessible pore volume. Gas adsorption studies confirmed the microporous nature of with a specific surface area (BET model) of 952 m ·g and a pore volume of 0.37 cm ·g . Extensive CO , N , O , CO, CH , C H , C H and C H gas adsorption experiments at 273 K and 298 K were carried out, which revealed the great adsorption selectivity of C H over CH (IAST selectivity factor 14.8 at 298 K). The sulfur-rich ligands and double framework interpenetration in 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 CO adsorption selectivities were obtained for CO /CH (11.7) and CO /N (27.2 for CO :N = 1:1, 56.4 for CO :N = 15:85 gas mixtures). The computational DFT calculations revealed the decisive role of the sulfur-containing heterocycle moieties in the adsorption of CO and C H . High CO adsorption selectivity values and a relatively low isosteric heat of CO adsorption (31.4 kJ·mol ) make the porous material a promising candidate for practical separation of biogas as well as for CO sequestration from flue gas or natural gas.