Titanium‐Oxo Cluster Assisted Fabrication of a Defect‐Rich Ti‐MOF Membrane Showing Versatile Gas‐Separation Performance

• Published in: Angewandte Chemie International Edition 2022-06, Vol.61 (26), p.e202203663-n/a
• Main Authors: Wang, Chen, Sun, Yanwei, Li, Libo, Krishna, Rajamani, Ji, Taotao, Chen, Sixing, Yan, Jiahui, Liu, Yi
• Format: Article
• Language: English
• Subjects: Carbon dioxide; Clusters; Fabrication; Gas Separation; Membranes; Metal-organic frameworks; Selectivity; Structural Defects; Ti-Oxo Clusters; Titanium
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.202203663

Although having shown great promise for efficient gas separation, relevant study of Ti‐MOF membranes remains very scarce, owing to limited Ti source types and uncertain factors which dominate the separation properties. In this work, we pioneered the use of the Ti8(μ2‐O)8(OOCC6H5)16 cluster as the Ti source of MIL‐125 membranes, which led to lower reaction temperature and higher missing‐linker number within the framework and therefore, enhanced CO2/N2 adsorption selectivity. The MIL‐125 membrane prepared by combining single‐mode microwave heating with tertiary growth displayed an ideal CO2/N2 selectivity of 38.7, which ranked the highest among all pristine pure MOF membranes measured under comparable conditions. In addition, the ideal H2/N2 and H2/CH4 selectivity was as high as 64.9 and 40.7, thus showing great promise for versatile utility in gas separation. With the titanium‐oxo cluster Ti8(μ2‐O)8(OOCC6H5)16 as the titanium source, a MIL‐125 metal–organic framework (MOF) membrane was prepared under mild reaction conditions through combining single‐mode microwave heating with tertiary growth. Using this titanium source and maintaining a lower reaction temperature increased the missing‐linker number in the MIL‐125 framework and therefore enhanced the CO2/N2 selectivity.