Selective Adsorption and Separation of ortho-Substituted Alkylaromatics with the Microporous Aluminum Terephthalate MIL-53

• Published in: Journal of the American Chemical Society Vol. 130; no. 43; pp. 14170 - 14178
• Main Authors: Alaerts, Luc, Maes, Michael, Giebeler, Lars, Jacobs, Pierre A., Martens, Johan A., Denayer, Joeri F. M., Kirschhock, Christine E. A., De Vos, Dirk E.
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 29.10.2008
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/ja802761z

The metal−organic framework MIL-53(Al) was tested for selective adsorption and separation of xylenes and ethylbenzene, ethyltoluenes, and cymenes using batch, pulse chromatographic, and breakthrough experiments. In all conditions tested, MIL-53 has the largest affinity for the ortho-isomer among each group of alkylaromatic compounds. Separations of the ortho-compounds from the other isomers can be realized using a column packed with MIL-53 crystallites. As evidenced by Rietveld refinements, specific interactions of the xylenes with the pore walls of MIL-53 determine selectivity. In comparison with the structurally similar metal−organic framework MIL-47, the selectivities among alkylaromatics found for MIL-53 are different. Separation of ethyltoluene and cymene isomers is more effective on MIL-53 than on MIL-47; the pores of MIL-53 seem to be a more suitable environment for hosting the larger ethyltoluene and cymene isomers than those of MIL-47.