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