Chen Zhonghang, Fang Peiyu, Li Jiangnan, Han Xue, Huang Wenhao, Cui Wenyue, Liu Zhiwei, Warren Mark R, Allan David, Cheng Peng, Yang Sihai, Shi Wei
Frontiers Science Center for New Organic Matter, Key Laboratory of Advanced Energy Materials Chemistry (MOE), and State Key Laboratory of Advanced Chemical Power Sources, College of Chemistry, Nankai University, Tianjin 300071, China.
Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
Natl Sci Rev. 2024 Oct 3;11(12):nwae342. doi: 10.1093/nsr/nwae342. eCollection 2024 Dec.
Due to almost identical boiling points of benzene and cyclohexane, the extraction of trace benzene from cyclohexane is currently performed the energy-intensive extractive distillation method. Their adsorptive separation by porous materials is hampered by their similar dimensions. Metal-organic frameworks (MOFs) with versatile pore environments are capable of molecular discrimination, but the separation of trace substrates in liquid-phase remains extremely challenging. Herein, we report a robust MOF (NKU-300) with triangular channels decorated with crown ether that can discriminate trace benzene from cyclohexane, exhibiting an unprecedented selectivity of 8615(10) for the mixture of benzene/cyclohexane (v/v = 1/1000). Remarkably, NKU-300 demonstrates exceptional selectivities for the extraction of benzene from cyclohexane over a wide range of concentrations of 0.1%-50% with ultrafast sorption kinetics and excellent stability. Single-crystal X-ray diffraction and computational modelling reveal that multiple supramolecular interactions cooperatively immobilise benzene molecules in the triangular channel, enabling superior separation performance. This study will promote the application of advanced sorbents with tailored binding sites for challenging industrial separations.
由于苯和环己烷的沸点几乎相同，目前从环己烷中萃取痕量苯采用的是能耗大的萃取精馏法。它们在尺寸上相似，这阻碍了用多孔材料对其进行吸附分离。具有多样孔环境的金属有机框架（MOF）能够进行分子识别，但在液相中分离痕量底物仍然极具挑战性。在此，我们报道了一种坚固的MOF（NKU-300），其三角形通道装饰有冠醚，能够从环己烷中区分痕量苯，对于苯/环己烷混合物（v/v = 1/1000）表现出前所未有的8615(10)的选择性。值得注意的是，NKU-300在0.1% - 50%的宽浓度范围内，对从环己烷中萃取苯表现出优异的选择性，具有超快的吸附动力学和出色的稳定性。单晶X射线衍射和计算模型表明，多种超分子相互作用协同将苯分子固定在三角形通道中，从而实现卓越的分离性能。这项研究将推动具有定制结合位点的先进吸附剂在具有挑战性的工业分离中的应用。
