Fan Hongwei, Peng Manhua, Strauss Ina, Mundstock Alexander, Meng Hong, Caro Jürgen
Institute of Physical Chemistry and Electrochemistry, Leibniz Universität Hannover, Callinstraße 3A, 30167 Hannover, Germany.
Institut für Festkörperphysik, Leibniz Universität Hannover, Appelstrasse 2, 30167 Hannover, Germany.
J Am Chem Soc. 2020 Apr 15;142(15):6872-6877. doi: 10.1021/jacs.0c00927. Epub 2020 Apr 1.
In this study, we propose a new concept of vertically aligned 2D covalent organic framework (COF) layers forming a membrane for efficient gas separation on the basis of precise size exclusion. Gas transport takes place through the COF interlayer space (typically 0.3-0.4 nm) rather than through the nanometer-sized pore apertures. Construction of such a unique membrane architecture was implemented via oriented growth of 2D COFs inside a skeleton of vertically aligned CoAl-layered double hydroxide (LDH) nanosheets. The resultant vertical COF-LZU1 membrane exhibits a high H permeance of ∼3600 GPU together with a desirable separation selectivity for gas mixtures such as H/CO (31.6) and H/CH (29.5), thus surpassing the 2008 Robeson upper bounds. The universality of this approach was demonstrated by successfully producing two types of high-quality vertical COF membranes with superior performance as well as outstanding running stability.
在本研究中，我们提出了一种基于精确尺寸排阻形成用于高效气体分离的膜的垂直排列二维共价有机框架（COF）层的新概念。气体传输通过COF层间空间（通常为0.3 - 0.4纳米）进行，而不是通过纳米尺寸的孔口。这种独特膜结构的构建是通过在垂直排列的CoAl层状双氢氧化物（LDH）纳米片骨架内二维COF的定向生长来实现的。所得的垂直COF-LZU1膜表现出约3600 GPU的高H渗透率以及对诸如H/CO（31.6）和H/CH（29.5）等气体混合物所需的分离选择性，从而超过了2008年的罗伯逊上限。通过成功制备两种具有优异性能以及出色运行稳定性的高质量垂直COF膜，证明了该方法的通用性。
