title: Carbohydrate-mediated purification of petrochemicals.
abstract: Metal-organic frameworks (MOFs) are known to facilitate energy-efficient separations of important industrial chemical feedstocks. Here, we report how a class of green MOFs-namely CD-MOFs-exhibits high shape selectivity toward aromatic hydrocarbons. CD-MOFs, which consist of an extended porous network of γ-cyclodextrins (γ-CDs) and alkali metal cations, can separate a wide range of benzenoid compounds as a result of their relative orientation and packing within the transverse channels formed from linking (γ-CD)6 body-centered cuboids in three dimensions. Adsorption isotherms and liquid-phase chromatographic measurements indicate a retention order of ortho- > meta- > para-xylene. The persistence of this regioselectivity is also observed during the liquid-phase chromatography of the ethyltoluene and cymene regioisomers. In addition, molecular shape-sorting within CD-MOFs facilitates the separation of the industrially relevant BTEX (benzene, toluene, ethylbenzene, and xylene isomers) mixture. The high resolution and large separation factors exhibited by CD-MOFs for benzene and these alkylaromatics provide an efficient, reliable, and green alternative to current isolation protocols. Furthermore, the isolation of the regioisomers of (i) ethyltoluene and (ii) cymene, together with the purification of (iii) cumene from its major impurities (benzene, n-propylbenzene, and diisopropylbenzene) highlight the specificity of the shape selectivity exhibited by CD-MOFs. Grand canonical Monte Carlo simulations and single component static vapor adsorption isotherms and kinetics reveal the origin of the shape selectivity and provide insight into the capability of CD-MOFs to serve as versatile separation platforms derived from renewable sources.
authors: †Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States.
authors: James M
authors: JM
authors: Holcroft
authors: †Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States.
authors: Karel J
authors: KJ
authors: Hartlieb
authors: Peyman Z
authors: PZ
authors: Moghadam
authors: ∥ Wolfson Northern Carbon Research Laboratories, School of Chemical Engineering and Advanced Materials, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom.
authors: Jon G
authors: JG
authors: Bell
authors: ⊥Department of Chemistry, University of California, Berkeley, California 94720-1460, United States.
authors: Gokhan
authors: G
authors: Barin
authors: †Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States.
authors: Daniel P
authors: DP
authors: Ferris
authors: ⊥Department of Chemistry, University of California, Berkeley, California 94720-1460, United States.
authors: Eric D
authors: ED
authors: Bloch
authors: #Joint Center of Excellence in Integrated Nano-Systems (JCIN), King Abdul-Aziz City for Science and Technology (KACST), P.O. Box 6086, Riyadh 11442, Kingdom of Saudi Arabia.
authors: Mohammed M
authors: MM
authors: Algaradah
authors: #Joint Center of Excellence in Integrated Nano-Systems (JCIN), King Abdul-Aziz City for Science and Technology (KACST), P.O. Box 6086, Riyadh 11442, Kingdom of Saudi Arabia.
authors: Majed S
authors: MS
authors: Nassar
authors: #Joint Center of Excellence in Integrated Nano-Systems (JCIN), King Abdul-Aziz City for Science and Technology (KACST), P.O. Box 6086, Riyadh 11442, Kingdom of Saudi Arabia.|⊗University Research Office, Intel Corporation, Building RNB-6-64, 2200 Mission College Boulevard, Santa Clara, California 95054-1549, United States.
authors: Youssry Y
authors: YY
authors: Botros
authors: ∥ Wolfson Northern Carbon Research Laboratories, School of Chemical Engineering and Advanced Materials, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom.
authors: K Mark
authors: KM
authors: Thomas
authors: ⊥Department of Chemistry, University of California, Berkeley, California 94720-1460, United States.
authors: Jeffrey R
authors: JR
authors: Long
authors: Randall Q
authors: RQ
authors: Snurr
authors: †Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States.
authors: J Fraser
authors: JF
authors: Stoddart