Extraordinary Separation of Acetylene‐Containing Mixtures with Microporous Metal–Organic Frameworks with Open O Donor Sites and Tunable Robustness through Control of the Helical Chain Secondary Building Units |
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| Authors: | Zizhu Yao Prof. Dr. Zhangjing Zhang Lizhen Liu Ziyin Li Prof. Dr. Wei Zhou Dr. Yunfeng Zhao Prof. Dr. Yu Han Prof. Dr. Banglin Chen Prof. Dr. Rajamani Krishna Prof. Dr. Shengchang Xiang |
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| Affiliation: | 1. Fujian Provincial Key Laboratory of Polymer Materials, Fujian Normal University, Fuzhou, P. R. China;2. NIST Center for Neutron Research, Gaithersburg, Maryland, USA;3. Advanced Membranes and Porous Materials Center, Physical Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia;4. Institute for New Energy Materials & Low-Carbon Technologies, School of Materials Science and Engineering, Tianjin University of Technology, Tianjin, P. R. China;5. Department of Chemistry, University of Texas at San Antonio, San Antonio, Texas, USA;6. Van't Hoff Institute for Molecular Sciences, University of Amsterdam, Amsterdam, The Netherlands |
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| Abstract: | Acetylene separation is a very important but challenging industrial separation task. Here, through the solvothermal reaction of CuI and 5‐triazole isophthalic acid in different solvents, two metal–organic frameworks (MOFs, FJU‐21 and FJU‐22 ) with open O donor sites and controllable robustness have been obtained for acetylene separation. They contain the same paddle‐wheel {Cu2(COO2)4} nodes and metal–ligand connection modes, but with different helical chains as secondary building units (SBUs), leading to different structural robustness for the MOFs. FJU‐21 and FJU‐22 are the first examples in which the MOFs’ robustness is controlled by adjusting the helical chain SBUs. Good robustness gives the activated FJU‐22 a , which has higher surface area and gas uptakes than the flexible FJU‐21 a . Importantly, FJU‐22 a shows extraordinary separation of acetylene mixtures under ambient conditions. The separation capacity of FJU‐22 a for 50:50 C2H2/CO2 mixtures is about twice that of the high‐capacity HOF‐3, and its actual separation selectivity for C2H2/C2H4 mixtures containing 1 % acetylene is the highest among reported porous materials. Based on first‐principles calculations, the extraordinary separation performance of C2H2 for FJU‐22 a was attributed to hydrogen‐bonding interactions between the C2H2 molecules with the open O donors on the wall, which provide better recognition ability for C2H2 than other functional sites, including open metal sites and amino groups. |
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| Keywords: | column breakthrough metal– organic frameworks open O donors selective gas adsorption structural diversity |
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