Can Metal-Organic Framework Separate 1-Butene from Butene Isomers?
The separation of 1-butene from the other isomers is an industrially important but challenging task because these isomers mainly differ only by the position of C═C double bond with many of their physical properties very similar. In this work, we propose using first-principles calculations that Fe-MOF-74 can be a promising candidate for the separation of 1-butene from all other isomers with high selectivity. We demonstrate that the underlying mechanism of this olefin separation is the steric interactions; that is, 1-butene with terminal double bond has the smallest steric interactions with the framework and therefore can approach the metal binding sites more closely for stronger π-complexation. This combined effect (π-complexation modulated by steric interactions) in MOFs with open metal sites can offer a promising design strategy for difficult separation of even longer olefin isomers by properly engineering the lengths and functional groups of the MOF linkers.
†Graduate School of EEWS, and ‡Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), 335 Gwahangno, Yuseong-gu, Daejeon 305-701, Republic of Korea.
Heejin
H
Kim
†Graduate School of EEWS, and ‡Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), 335 Gwahangno, Yuseong-gu, Daejeon 305-701, Republic of Korea.
Yousung
Y
Jung
MOF-74; alpha olefin; first principles; pi-complexation; steric effect