Xu Ming, Tang Wen-Qi, Meng Sha-Sha, Gu Zhi-Yuan
Jiangsu Key Laboratory of Biofunctional Materials, Jiangsu Collaborative Innovation Center of Biomedical Functional Materials, Jiangsu Key Laboratory of New Power Batteries, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023, China.
Chem Soc Rev. 2025 Feb 3;54(3):1613-1633. doi: 10.1039/d4cs00796d.
Xylene isomers, including -xylene (X), -xylene (X), -xylene (X), and ethyl benzene (EB), are important raw materials in industry. The separation of xylene isomers has been recognized as one of the "seven chemical separations to change the world". However, because of their similar physicochemical properties, totally separating four xylene isomers has remained a big challenge until now. Metal-organic frameworks (MOFs) have emerged as promising separators to achieve this goal because MOFs synergistically provide multiple mechanisms at the molecular scale. In this review, we summarize the recent progress of MOFs as separators for the separation of xylenes based on four main separation mechanisms: the molecular sieving effect, gating mechanism, thermodynamic interactions, and kinetic diffusion. We concentrate on the applications of MOFs in the field of chromatography, single-component vapor adsorption, liquid-phase competitive adsorption, breakthrough, and membrane separation. Finally, we conclude with the possible direction for designing high-performance MOF separators and briefly discuss the existing challenges in this area.
二甲苯异构体，包括对二甲苯（p-Xylene，PX）、间二甲苯（m-Xylene，MX）、邻二甲苯（o-Xylene，OX）和乙苯（Ethyl Benzene，EB），是重要的工业原料。二甲苯异构体的分离被认为是“改变世界的七大化学分离”之一。然而，由于它们相似的物理化学性质，迄今为止，完全分离四种二甲苯异构体仍然是一个巨大的挑战。金属有机框架材料（MOFs）已成为实现这一目标的有前景的分离材料，因为MOFs在分子尺度上协同提供多种分离机制。在这篇综述中，我们基于分子筛分效应、门控机制、热力学相互作用和动力学扩散这四种主要分离机制，总结了MOFs作为二甲苯分离材料的最新进展。我们重点关注MOFs在色谱、单组分蒸汽吸附、液相竞争吸附、突破和膜分离领域的应用。最后，我们总结了设计高性能MOF分离材料的可能方向，并简要讨论了该领域目前存在的挑战。
