A MOF Glass Membrane for Gas Separation

• Published in: Angewandte Chemie International Edition Vol. 59; no. 11; pp. 4365 - 4369
• Main Authors: Wang, Yuhan, Jin, Hua, Ma, Qiang, Mo, Kai, Mao, Haizhuo, Feldhoff, Armin, Cao, Xingzhong, Li, Yanshuo, Pan, Fusheng, Jiang, Zhongyi
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 09.03.2020
• Edition: International ed. in English
• Subjects: Aluminum oxide; Carbon dioxide; Crystal defects; Fabrication; Gas separation; Glass; glasses; Grain boundaries; Membranes; Metal-organic frameworks; Methane; molecular sieves; Polycrystals; Porosity; Upper bounds; Vitrification; glasses; membranes; molecular sieves; gas separation; metal-organic frameworks
• ISSN: 1433-7851; 1521-3773; 1521-3773
• DOI: 10.1002/anie.201915807

Metal–organic framework (MOF) glasses are promising candidates for membrane fabrication due to their significant porosity, the ease of processing, and most notably, the potential to eliminate the grain boundary that is unavoidable for polycrystalline MOF membranes. Herein, we developed a ZIF‐62 MOF glass membrane and exploited its intrinsic gas‐separation properties. The MOF glass membrane was fabricated by melt‐quenching treatment of an in situ solvothermally synthesized polycrystalline ZIF‐62 MOF membrane on a porous ceramic alumina support. The molten ZIF‐62 phase penetrated into the nanopores of the support and eliminated the formation of intercrystalline defects in the resultant glass membrane. The molecular sieving ability of the MOF membrane is remarkably enhanced via vitrification. The separation factors of the MOF glass membrane for H2/CH4, CO2/N2 and CO2/CH4 mixtures are 50.7, 34.5, and 36.6, respectively, far exceeding the Robeson upper bounds. Retained properties: A MOF glass membrane was synthesized by melt‐quenching a solvothermally synthesized ZIF‐62 polycrystalline membrane on an alumina support. The glass membrane is free of intercrystalline defects and acts as a molecular sieve for the separation of light gases. The separation performance for H2/CH4, CO2/N2, and CO2/CH4 far exceeds the respective Robeson upper bounds.