The trade-off between physical adsorption capacity and selectivity of porous materials is a major barrier for efficient gas separation and purification through physisorption. We report control over pore chemistry and size in metal coordination networks with hexafluorosilicate and organic linkers for the purpose of preferential binding and orderly assembly of acetylene molecules through cooperative host-guest and/or guest-guest interactions. The specific binding sites for acetylene are validated by modeling and neutron powder diffraction studies. The energies associated with these binding interactions afford high adsorption capacity (2.1 millimoles per gram at 0.025 bar) and selectivity (39.7 to 44.8) for acetylene at ambient conditions. Their efficiency for the separation of acetylene/ethylene mixtures is demonstrated by experimental breakthrough curves (0.73 millimoles per gram from a 1/99 mixture).
|Original language||English (US)|
|Number of pages||4|
|State||Published - May 19 2016|
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: This work is supported by the National Natural Science Foundation of China (grants 21222601, 21436010, and 21476192), Zhejiang Provincial Natural Science Foundation of China (grant LR13B060001), Ten Thousand Talent Program of China (to H.X.), the Welch Foundation (grant AX-1730), King Abdullah Science and Technology University Office of Competitive Research Funds (grant URF/1/1672-01-01), and the Science Foundation Ireland (award 13/RP/B2549 to M.Z.). We thank T. L. Hu, Y. F. Zhao, W. D. Shan, and M. D. Jiang for their help and arrangement of the breakthrough experiments; A. Kumar for help with sample characterization; and Z. G. Zhang and B. G. Su for discussions of the experiments. Metrical data for the solid-state structures of SIFSIX-2-Cu-i-C2D2 and SIFSIX-1-Cu-C2D2 are available free of charge from the Cambridge Crystallographic Data Centre under reference numbers CCDC 1471795 and 1471796.