Wang Dechao, Xin Yangyang, Li Xiaoqian, Ning Hailong, Wang Yudeng, Yao Dongdong, Zheng Yaping, Meng Zhuoyue, Yang Zhiyuan, Pan Yuting, Li Peipei, Wang Hongni, He Zhongjie, Fan Wendi
School of Chemistry and Chemical Engineering, Northwestern Polytechnical University, Xi'an 710129, P. R. China.
College of Chemistry and Chemical Engineering, Xi'an University of Science and Technology, Xi'an 710021, P. R. China.
ACS Appl Mater Interfaces. 2021 Jan 20;13(2):2600-2609. doi: 10.1021/acsami.0c18707. Epub 2021 Jan 6.
Porous liquids (PLs), an emerging kind of liquid materials with permanent porosity, have attracted increasing attention in gas capture. However, directly turning metal-organic frameworks (MOFs) into PLs via a covalent linkage surface engineering strategy has not been reported. Additionally, challenges including reducing the cost and simplifying the preparation process are daunting. Herein, we proposed a general method to transform Universitetet i Oslo (UiO)-66-OH MOFs into PLs by surface engineering with organosilane (OS) and oligomer species via covalent bonding linkage. The oligomer species endow UiO-66-OH with superior fluidity at room temperature. Meanwhile, the resulting PLs showed great potential in both CO adsorption and CO/N selective separation. The residual porosity of PLs was verified by diverse characterizations and molecular simulations. Besides, CO selective capture sites were determined by grand canonical Monte Carlo (GCMC) simulation. Furthermore, the universality of the covalent linkage surface engineering strategy was confirmed using different classes of oligomer species and another MOF (ZIF-8-bearing amino groups). Notably, this strategy can be extended to construct other PLs by taking advantages of the rich library of oligomer species, thus making PLs promising candidates for further applications in energy and environment-related fields, such as gas capture, separation, and catalysis.
多孔液体（PLs）是一种具有永久孔隙率的新型液体材料，在气体捕获方面受到越来越多的关注。然而，通过共价连接表面工程策略将金属有机框架（MOFs）直接转化为PLs尚未见报道。此外，包括降低成本和简化制备过程在内的挑战也令人生畏。在此，我们提出了一种通用方法，通过有机硅烷（OS）和低聚物物种的共价键连接表面工程，将奥斯陆大学（UiO）-66-OH MOFs转化为PLs。低聚物物种赋予UiO-66-OH在室温下优异的流动性。同时，所得的PLs在CO吸附和CO/N选择性分离方面均显示出巨大潜力。通过多种表征和分子模拟验证了PLs的残余孔隙率。此外，通过巨正则蒙特卡罗（GCMC）模拟确定了CO选择性捕获位点。此外，使用不同类别的低聚物物种和另一种MOF（含氨基的ZIF-8）证实了共价连接表面工程策略的通用性。值得注意的是，利用丰富的低聚物物种库，该策略可扩展用于构建其他PLs，从而使PLs成为能源和环境相关领域（如气体捕获、分离和催化）进一步应用的有前景的候选材料。
