Porous materials have been extensively explored to facilitate the development of energy-efficient separation processes towards handling industrial challenges.Herein,a microporous charge-assisted hydrogen-bonded organi...Porous materials have been extensively explored to facilitate the development of energy-efficient separation processes towards handling industrial challenges.Herein,a microporous charge-assisted hydrogen-bonded organic framework,HOF-35,was assembled from 2,3,5,6-tetrakis(4-carboxyphenyl)pyrazine with dimethylamine formed from the decomposition of N,N-dimethylformamide under solvothermal conditions.Single crystal X-ray diffraction(SCXRD)analysis reveals that HOF-35 was assembled from divalent H_(2)L^(2-) anions and dimethylammonium cations via hydrogen bonding interactions.Three single-crystal to single-crystal transformations were achieved through two-step solvent exchanges followed by a desolvent process,resulting in the activated sample HOF-35a with a Brunauer-Emmett-Teller surface area of 464 m^(2)g^(-1) according to CO_(2)sorption experiment at 196 K.In particular,HOF-35a can selectively adsorb o-xylene over m-xylene,p-xylene,and ethylbenzene on the basis of multicomponent liquid-phase adsorption results.SCXRD studies disclose the exact binding sites and multiple host-vip interactions of the four C8 molecules accommodated in this HOF.Thermogravimetric-differential scanning calorimetry analyses further estimate the highest adsorption enthalpy for o-xylene among these four C8 molecules,accounting for its preferential adsorption in the activated HOF from a thermodynamic perspective.Time-dependent liquid-phase adsorption experiments unveil the kinetic diffusion of C8 mixture.Obviously,the thermodynamic effect in combination with the kinetic diffusion process synergistically promotes the above-mentioned selective separation.展开更多
A microporous supramolecular framework with high water and thermal stability can selectively absorb water molecules over methanol or ethanol due to the suitable channels.The model separation test on columns shows that...A microporous supramolecular framework with high water and thermal stability can selectively absorb water molecules over methanol or ethanol due to the suitable channels.The model separation test on columns shows that an ultra-pure ethanol(99.9%)can be obtained from the mixture of ethanol/water(95:5).Additionally,after refluxing the desolvated sample in 95%ethanol at 60℃for 5 h,the purity of ethanol rises up to 97.43%,which is obviously higher than 96.56%for 4 A molecular sieves.展开更多
基金supported by the National Natural Science Foundation of China(22235001,22175020,22131005,22261132512,22225802)the Xiaomi Young Scholar Program,the Fundamental Research Funds for the Central Universities(FRF-EYIT-23-02,QNXM2023)the Guizhou University and the University of Science and Technology Beijing。
文摘Porous materials have been extensively explored to facilitate the development of energy-efficient separation processes towards handling industrial challenges.Herein,a microporous charge-assisted hydrogen-bonded organic framework,HOF-35,was assembled from 2,3,5,6-tetrakis(4-carboxyphenyl)pyrazine with dimethylamine formed from the decomposition of N,N-dimethylformamide under solvothermal conditions.Single crystal X-ray diffraction(SCXRD)analysis reveals that HOF-35 was assembled from divalent H_(2)L^(2-) anions and dimethylammonium cations via hydrogen bonding interactions.Three single-crystal to single-crystal transformations were achieved through two-step solvent exchanges followed by a desolvent process,resulting in the activated sample HOF-35a with a Brunauer-Emmett-Teller surface area of 464 m^(2)g^(-1) according to CO_(2)sorption experiment at 196 K.In particular,HOF-35a can selectively adsorb o-xylene over m-xylene,p-xylene,and ethylbenzene on the basis of multicomponent liquid-phase adsorption results.SCXRD studies disclose the exact binding sites and multiple host-vip interactions of the four C8 molecules accommodated in this HOF.Thermogravimetric-differential scanning calorimetry analyses further estimate the highest adsorption enthalpy for o-xylene among these four C8 molecules,accounting for its preferential adsorption in the activated HOF from a thermodynamic perspective.Time-dependent liquid-phase adsorption experiments unveil the kinetic diffusion of C8 mixture.Obviously,the thermodynamic effect in combination with the kinetic diffusion process synergistically promotes the above-mentioned selective separation.
基金support from the National Key Research and Development Program of China(No.2017YFA0700102)the National Natural Science Foundation of China(Nos.21871266 and 21731006)+1 种基金the Key Research Program of Frontier Science CAS(No.QYZDY-SSW-SLH025)Youth Innovation Promotion Association CAS.
文摘A microporous supramolecular framework with high water and thermal stability can selectively absorb water molecules over methanol or ethanol due to the suitable channels.The model separation test on columns shows that an ultra-pure ethanol(99.9%)can be obtained from the mixture of ethanol/water(95:5).Additionally,after refluxing the desolvated sample in 95%ethanol at 60℃for 5 h,the purity of ethanol rises up to 97.43%,which is obviously higher than 96.56%for 4 A molecular sieves.
