A stable microporous framework with multiple accessible adsorption sites for high capacity adsorption and efficient separation of light hydrocarbons

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Vol. 466; p. 143170
• Main Authors: Zhang, Xiao-Xia, Guo, Xing-Zhe, Chen, Shui-Sheng, Kang, Hong-Wei, Zhao, Yue, Gao, Ji-Xing, Xiong, Guang-Zu, Hou, Lei
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.06.2023
• Subjects: Dynamic breakthrough experiment; Gas adsorption; GCMC simulation; Hydroxyl-functionalized Ni2+-MOF; Selective separation; Selective separation; GCMC simulation; Hydroxyl-functionalized Ni2+-MOF; Gas adsorption; Dynamic breakthrough experiment
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2023.143170

[Display omitted] •Design high thermally and chemically stable Ni2+-MOF;•Multi accessible adsorption sites with good gas uptake capacity;•Favorable selectivity for binary mixtures by breakthrough experiments;•The synergistic host–guest interactions confirmed by GCMC simulation. Metal-organic frameworks (MOFs), a type of designable porous materials, are effectively employed to realize light hydrocarbons storage and separation in favor of energy conservation and environmental protection, superior to traditional separation technology. Significantly, a novel MOF, Ni2(L)2(HCOO)2·4H2O (1) has been constructed from a bifunctional group ligand of 3-hydroxy-4-(4H-1,2,4-triazol-4-yl) benzoic acid ligand (HL). MOF 1 possesses stable porous structure with narrow channels functionalized with multiple accessible adsorption sites of hydroxy group, carboxyl oxygen atoms from the L− and HCOO−, exhibiting a well trade-off between good capacity and selectivity for light hydrocarbons. The single-component sorption isotherm results of Ni2+ based MOF not only shows good gas sorption capacity for light hydrocarbons of C2H2, C2H6, C2H4, C3H8, and greenhouse gas CO2, especially remarkable uptake for C2H2 (122.0 cm3 g−1 at ambient condition), but also favorable selectivity for binary mixtures of C2H2/CH4, C2H6/CH4, C3H8/CH4, C2H4/CH4, C2H2/C2H4 as well as C3H8/C2H6/CH4 ternary mixture, as confirmed by ideal adsorbed solution theory (IAST) calculations, and dynamic breakthrough experiment. Grand canonical Monte Carlo (GCMC) simulation reveals the multiple synergism of accessible adsorption sites including functional OH groups, carboxylate groups, HCOO− and π···π stacking interaction between guest molecules and host-pore are crucial to contribute selective gas adsorption of light hydrocarbons.