title: Selective adsorption and separation of ortho-substituted alkylaromatics with the microporous aluminum terephthalate MIL-53.
abstract: 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.
authors.affiliation: Centre for Surface Chemistry and Catalysis, Katholieke Universiteit Leuven, Kasteelpark Arenberg 23, 3001 Leuven, Belgium.
authors.forename: Luc
authors.initials: L
authors.lastname: Alaerts
authors.forename: Michael
authors.initials: M
authors.lastname: Maes
authors.forename: Lars
authors.initials: L
authors.lastname: Giebeler
authors.forename: Pierre A
authors.initials: PA
authors.lastname: Jacobs
authors.forename: Johan A
authors.initials: JA
authors.lastname: Martens
authors.forename: Joeri F M
authors.initials: JF
authors.lastname: Denayer
authors.forename: Christine E A
authors.initials: CE
authors.lastname: Kirschhock
authors.forename: Dirk E
authors.initials: DE
authors.lastname: De Vos