Sapianik Aleksandr A, Dudko Evgeny R, Kovalenko Konstantin A, Barsukova Marina O, Samsonenko Denis G, Dybtsev Danil N, Fedin Vladimir P
Functional Materials Design, Discovery and Development Research Group (FMD3), Advanced Membranes and Porous Materials Center (AMPM), Division of Physical Sciences and Engineering (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia.
Nikolaev Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences, Novosibirsk 630090, Russia.
ACS Appl Mater Interfaces. 2021 Mar 31;13(12):14768-14777. doi: 10.1021/acsami.1c02812. Epub 2021 Mar 17.
Separation of hydrocarbon molecules, such as benzene/cyclohexane and -xylene/-xylene/-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 [LiZn(bpy)(ndc)] (, bpy = 4,4'-bipyridine, ndc = 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 demonstrates outstanding selective sorption properties and becomes a new benchmark for -/-xylene separation. In addition, is stable enough to carry out at least three separation cycles of benzene/cyclohexane mixtures or ternary -xylene/-xylene/-xylene mixtures both in the liquid and in the vapor phase. Insights into the performance of are gained from X-ray structural studies of each aromatic guest inclusion compound.
烃类分子的分离，如苯/环己烷和二甲苯异构体的分离，因其作为化学原料的广泛应用而备受关注，但由于它们相似的沸点和相近的分子尺寸，分离具有挑战性。物理吸附分离可能为解决这一问题提供一种节能方案，但设计和合成对其中一种烃类具有高选择性的吸附剂仍然是一个很大程度上未得到满足的挑战。在此，我们报道了一种新型异金属金属有机框架材料[LiZn(bpy)(ndc)]（bpy = 4,4'-联吡啶，ndc = 萘-1,4-二羧酸酯），其具有独特的曲折形通道，通道上装饰有芳香吸附位点，并对其苯/环己烷和二甲苯的气液分离性能进行了研究。对于等摩尔的苯/环己烷混合物，在吸附相中苯的含量可能会超过环己烷10倍。对于二甲苯，该微孔框架材料表现出出色的选择性吸附性能，成为间二甲苯/对二甲苯分离的新基准。此外，该材料足够稳定，能够在液相和气相中对苯/环己烷混合物或三元二甲苯异构体混合物进行至少三个分离循环。通过对每种芳香客体包合物的X射线结构研究，深入了解了该材料的性能。
