Hongwei Fan1, Manhua Peng2, Ina Strauss1, Alexander Mundstock1, Hong Meng3, Jürgen Caro4,5. 1. Institute of Physical Chemistry and Electrochemistry, Leibniz Universität Hannover, Callinstraße 3A, 30167, Hannover, Germany. 2. Institut für Festkörperphysik, Leibniz Universität Hannover, Appelstrasse 2, 30167, Hannover, Germany. 3. Beijing Key Laboratory of Membrane Science and Technology, Beijing University of Chemical Technology, 100029, Beijing, PR China. menghong@mail.buct.edu.cn. 4. Institute of Physical Chemistry and Electrochemistry, Leibniz Universität Hannover, Callinstraße 3A, 30167, Hannover, Germany. juergen.caro@pci.uni-hannover.de. 5. School of Chemistry and Chemical Engineering, South China University of Technology, 510640, Guangzhou, PR China. juergen.caro@pci.uni-hannover.de.
Abstract
Covalent organic frameworks (COFs) are promising materials for advanced molecular-separation membranes, but their wide nanometer-sized pores prevent selective gas separation through molecular sieving. Herein, we propose a MOF-in-COF concept for the confined growth of metal-organic framework (MOFs) inside a supported COF layer to prepare MOF-in-COF membranes. These membranes feature a unique MOF-in-COF micro/nanopore network, presumably due to the formation of MOFs as a pearl string-like chain of unit cells in the 1D channel of 2D COFs. The MOF-in-COF membranes exhibit an excellent hydrogen permeance (>3000 GPU) together with a significant enhancement of separation selectivity of hydrogen over other gases. The superior separation performance for H2/CO2 and H2/CH4 surpasses the Robeson upper bounds, benefiting from the synergy combining precise size sieving and fast molecular transport through the MOF-in-COF channels. The synthesis of different combinations of MOFs and COFs in robust MOF-in-COF membranes demonstrates the versatility of our design strategy.
Covn class="Chemical">alent organic frameworks (COFs) are promising materials for advanced molecular-separation membranes, but their wide nanometer-sized pores prevent selective gas separation through molecular sieving. Herein, we propose a MOF-in-COFconcept for the confined growth of metal-organic framework (MOFs) inside a supported COF layer to prepare MOF-in-COF membranes. These membranes feature a unique MOF-in-COF micro/nanopore network, presumably due to the formation of MOFs as a pearl string-like chain of unit cells in the 1D channel of 2D COFs. The MOF-in-COF membranes exhibit an excellent hydrogen permeance (>3000 GPU) together with a significant enhancement of separation selectivity of hydrogen over other gases. The superior separation performance for H2/CO2 and H2/CH4 surpasses the Robeson upper bounds, benefiting from the synergy combining precise size sieving and fast molecular transport through the MOF-in-COF channels. The synthesis of different combinations of MOFs and COFs in robust MOF-in-COF membranes demonstrates the versatility of our design strategy.
Authors: Mi Young Jeon; Donghun Kim; Prashant Kumar; Pyung Soo Lee; Neel Rangnekar; Peng Bai; Meera Shete; Bahman Elyassi; Han Seung Lee; Katabathini Narasimharao; Sulaiman Nasir Basahel; Shaeel Al-Thabaiti; Wenqian Xu; Hong Je Cho; Evgenii O Fetisov; Raghuram Thyagarajan; Robert F DeJaco; Wei Fan; K Andre Mkhoyan; J Ilja Siepmann; Michael Tsapatsis Journal: Nature Date: 2017-03-15 Impact factor: 49.962
Authors: A Knebel; B Geppert; K Volgmann; D I Kolokolov; A G Stepanov; J Twiefel; P Heitjans; D Volkmer; J Caro Journal: Science Date: 2017-10-20 Impact factor: 47.728