北京工业大学李建荣团队在最新研究中，利用MOF分子筛去除环己烷中痕量苯。该研究于2024年12月5日发表于国际一流学术期刊《美国化学会杂志》上。

据介绍，环己烷（Cy）通常由苯（Bz）的催化加氢产生，被大量用作尼龙聚合物的溶剂或原料。由于其分子结构和物理性质相似，从Cy产品中去除微量未反应的Bz在技术上是困难的。

在该研究中，该研究团队报道了金属有机框架（MOF）吸附剂对环己烷（Cy）和苯（Bz）的分子筛分作用，在其液体混合物（v/v = 1:1, 1:10和1:20）中具有创纪录的高Bz/Cy吸附选择性（216, 723和1027），并且即使在气相低分压（例如，8.2 Pa时2.49 mmol/g）或液相低含量（例如，20 ppm时128 mg/g）下也能有效捕获Bz分子。

在室温下对该吸附剂进行一次简单的剥离步骤，就可以从液态Cy中去除99%以上的微量Bz (1000 ppm)，从而生产出纯度为99.999%的Cy。对MOF无客体相和负载Bz相的单晶结构分析表明，MOF对Bz和Cy具有独特的吸附性能，其狭缝状孔径和多个弱主客体和客体客体相互作用的强联合，是其独特的吸附性能的原因。

附：英文原文

Title: Removal of Trace Benzene from Cyclohexane Using a MOF Molecular Sieve

Author: Rui-Chao Zhao, Lin-Hua Xie, Xiao-Min Liu, Zhe Liu, Xiang-Yu Li, Jian-Rong Li

Issue&Volume: December 5, 2024

Abstract: Cyclohexane (Cy), commonly produced by the catalytic hydrogenation of benzene (Bz), is used in large quantities as a solvent or feedstock for nylon polymers. Removing trace unreacted Bz from the Cy product is technically difficult due to their similar molecular structures and physical properties. Herein, we report that a metal–organic framework (MOF) adsorbent shows a molecular sieving effect for Bz and Cy with record-high Bz/Cy adsorption selectivities (216, 723, and 1027) in their liquid mixtures (v/v = 1:1, 1:10, and 1:20), and traps Bz molecules effectively even at low partial pressure in the vapor phase (e.g., 2.49 mmol/g at 8.2 Pa) or at low content in liquid-phase Cy (e.g., 128 mg/g at 20 ppm). Over 99% removal of trace Bz (1000 ppm) from liquid Cy could be achieved in one simple stripping step at room temperature using this sorbent, producing a Cy with >99.999% purity. Single-crystal structure analyses for guest-free and Bz-loaded phases of the MOF disclosed that a narrow slit-like pore aperture and the strong uniting of multiple weak host–guest and guest–guest interactions are the co-origin of its distinct adsorption property for Bz and Cy.

DOI: 10.1021/jacs.4c13208

Source: https://pubs.acs.org/doi/abs/10.1021/jacs.4c13208