Separation of hydrocarbon molecules, such as benzene/cyclohexane and o-xylene/m-xylene/p-xylene, is relevant due to their widespread application as chemical feedstock but challenging because of their similar boiling points and close molecular sizes. Physisorption separation could offer an energy-efficient solution to this problem, but the design and synthesis of sorbents that exhibit high selectivity for one of the hydrocarbons remain a largely unmet challenge. Herein, we report a new heterometallic MOF with a unique tortuous shape of channels decorated with aromatic sorption sites [Li2Zn2(bpy)(ndc)3] (NIIC-30(Ph), bpy = 4,4'-bipyridine, ndc2- = naphthalene-1,4-dicarboxylate) and study of its benzene/cyclohexane and xylene vapor and liquid separation. For an equimolar benzene/cyclohexane mixture, it is possible to achieve a 10-fold excess of benzene in the adsorbed phase. In the case of xylenes, microporous framework NIIC-30(Ph) demonstrates outstanding selective sorption properties and becomes a new benchmark for m-/o-xylene separation. In addition, NIIC-30(Ph) is stable enough to carry out at least three separation cycles of benzene/cyclohexane mixtures or ternary o-xylene/m-xylene/p-xylene mixtures both in the liquid and in the vapor phase. Insights into the performance of NIIC-30(Ph) are gained from X-ray structural studies of each aromatic guest inclusion compound.
|Original language||English (US)|
|Journal||ACS Applied Materials & Interfaces|
|State||Published - Mar 17 2021|
Bibliographical noteKAUST Repository Item: Exported on 2021-03-22
Acknowledgements: Synthesis of new heterometallic MOF and its luminescence investigation were supported by the Russian Science Foundation grant (No.1973-00171), and X-ray structural analysis and sorption/selectivity investigation were supported by the Russian Science Foundation grant (No. 19-73-20087). The authors thank Dr. P. V. Dorovatovskii and Dr. V. A. Lazarenko for their assistance during synchrotron XRD experiments.
ASJC Scopus subject areas
- Materials Science(all)