南开大学张振杰团队报道了自底向上合成8-连接三维共价有机框架高效分离乙烯/乙烷。相关研究成果发表在2022年3月21日出版的国际学术期刊《美国化学会杂志》。

开发从乙烯/乙烷混合物中提纯乙烯的成本/能源效率高的分离技术非常重要，但在工业过程中非常具有挑战性。

该文中，研究人员采用自下而上的[8+2]构建方法，合理设计并合成了具有8个连接bcu网络的三维共价有机框架（COFs），该框架可以高效地从乙烯/乙烷混合物中选择性去除乙烷。这些COF材料由cthemomer设计的八位醛单体与线性二氨基连接物缩合反应制成，具有高结晶度、良好的结构稳定性和高孔隙率。由于这些COFs具有组织良好的微孔和非极性/惰性孔环境，因此它们对乙烷的吸附能力高，对乙烯的选择性好，是乙烯净化的最佳乙烷选择性吸附剂之一。通过单次吸附法生产的高纯度乙烯（>99.99%）的动态突破实验，验证了其优异的乙烯/乙烷分离性能。分离性能超过了所有报道的C₂H₆选择性COFs，甚至超过了一些基准金属-有机框架。

研究工作为高附加值气体净化用新型吸附剂的设计提供了重要指导。

附：英文原文

Title: Bottom-Up Synthesis of 8-Connected Three-Dimensional Covalent Organic Frameworks for Highly Efficient Ethylene/Ethane Separation

Author: Fazheng Jin, En Lin, Tonghai Wang, Shubo Geng, Ting Wang, Wansheng Liu, Fanhao Xiong, Zhifang Wang, Yao Chen, Peng Cheng, Zhenjie Zhang

Issue&Volume: March 21, 2022

Abstract: Developing cost-/energy-efficient separation techniques for purifying ethylene from an ethylene/ethane mixture is highly important but very challenging in the industrial process. Herein, using a bottom-up [8 + 2] construction approach, we rationally designed and synthesized three three-dimensional covalent organic frameworks (COFs) with 8-connected bcu networks, which can selectively remove ethane from an ethylene/ethane mixture with high efficiency. These COF materials, which are fabricated by the condensation reaction of a customer-designed octatopic aldehyde monomer with linear diamino linkers, possess high crystallinity, good structural robustness, and high porosity. Attributed to the well-organized micro-sized pores with a nonpolar/inert pore environment, these COFs display high ethane adsorption capacity and good selectivity over ethylene, making them among the best ethane-selective adsorbents for ethylene purification. Their excellent ethylene/ethane separation performance is validated by dynamic breakthrough experiments with high-purity ethylene (>99.99%) produced through a single adsorption process. The separation performance surpasses all reported C2H6-selective COFs and even some benchmark metal–organic frameworks. This work provides important guidance for the design of new adsorbents for value-added gas purification.

DOI: 10.1021/jacs.2c01058

Source: https://pubs.acs.org/doi/10.1021/jacs.2c01058