{"title":"A polyhedron-based metal-organic framework with electronegative donor sites for efficient C2H6/C2H4 separation","authors":"","doi":"10.1016/j.molstruc.2024.140166","DOIUrl":null,"url":null,"abstract":"<div><div>Ethylene is an important chemical raw material which is widely used in the production of chemical fibers, plastics, rubber, coatings, as well as medicines, and its separation from the gas mixtures of C<sub>2</sub>H<sub>6</sub>/C<sub>2</sub>H<sub>4</sub> is of great importance but a challenging task due to their similar physical properties and molecular dimensions. Herein, we report the C<sub>2</sub>H<sub>6</sub> and C<sub>2</sub>H<sub>4</sub> sorption studies on a robust anionic metal-organic framework (MOF) {(NH<sub>2</sub>Me<sub>2</sub>)[Co<sub>3</sub>(μ<sub>3<img></sub>OH)(TPT)(TZB)<sub>3</sub>](H<sub>2</sub>O)<sub>6</sub>(DMA)<sub>6</sub>}<sub>n</sub> (Co-MOF) formed by connection of Co<sub>3</sub>(OH) clusters by two N-rich organic ligands 2,4,6-tri(4-pyridyl)-1,3,5-triazine (TPT) and 4-(1H-Tetrazol-5-yl)benzoic acid (H<sub>2</sub>TZB). The prepared Co-MOF features a polyhedron stacking network structure composed of trigonal bipyramidal cages and octahedral cage which both contribute to a high C<sub>2</sub>H<sub>6</sub> uptake capacity of 6.48 mmol/g and a decent C<sub>2</sub>H<sub>6</sub>/C<sub>2</sub>H<sub>4</sub> selectivity of 1.54 at 298 K and 1 bar. Grand Canonical Monte Carlo (GCMC) simulation results agree well with the experimental tendency, both in the adsorption isotherms and sorption heats, which demonstrated that the suitable pore surfaces with electronegative donor sites generated multiple C<img>H ⋅⋅⋅O/N and C<img>H ⋅⋅⋅π interactions between the framework and C<sub>2</sub>H<sub>6</sub>, resulting in a stronger interaction between the MOF skeleton and C<sub>2</sub>H<sub>6</sub> molecule than C<sub>2</sub>H<sub>4</sub> as reflected by the dispersion-corrected density functional theory (DFT) calculation.</div></div>","PeriodicalId":16414,"journal":{"name":"Journal of Molecular Structure","volume":null,"pages":null},"PeriodicalIF":4.0000,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Molecular Structure","FirstCategoryId":"92","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0022286024026759","RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
引用次数: 0
Abstract
Ethylene is an important chemical raw material which is widely used in the production of chemical fibers, plastics, rubber, coatings, as well as medicines, and its separation from the gas mixtures of C2H6/C2H4 is of great importance but a challenging task due to their similar physical properties and molecular dimensions. Herein, we report the C2H6 and C2H4 sorption studies on a robust anionic metal-organic framework (MOF) {(NH2Me2)[Co3(μ3OH)(TPT)(TZB)3](H2O)6(DMA)6}n (Co-MOF) formed by connection of Co3(OH) clusters by two N-rich organic ligands 2,4,6-tri(4-pyridyl)-1,3,5-triazine (TPT) and 4-(1H-Tetrazol-5-yl)benzoic acid (H2TZB). The prepared Co-MOF features a polyhedron stacking network structure composed of trigonal bipyramidal cages and octahedral cage which both contribute to a high C2H6 uptake capacity of 6.48 mmol/g and a decent C2H6/C2H4 selectivity of 1.54 at 298 K and 1 bar. Grand Canonical Monte Carlo (GCMC) simulation results agree well with the experimental tendency, both in the adsorption isotherms and sorption heats, which demonstrated that the suitable pore surfaces with electronegative donor sites generated multiple CH ⋅⋅⋅O/N and CH ⋅⋅⋅π interactions between the framework and C2H6, resulting in a stronger interaction between the MOF skeleton and C2H6 molecule than C2H4 as reflected by the dispersion-corrected density functional theory (DFT) calculation.
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