A microporous multi‐cage metal–organic framework for an effective one‐step separation of branched alkanes feeds

The improvement of the Total Isomerization Process (TIP) for the production of high-quality gasoline with the ultimate goal of reaching a Research Octane Number (RON) higher than 92 requires the use of specific sorbents to separate pentane and hexane isomers into classes of linear, mono- and di-branched isomers. Herein we report the design of a new multi-cage microporous Fe(III)-MOF (referred to as MIP-214, MIP stands for materials of the Institute of Porous Materials of Paris) with a flu-e topology, incorporating an asymmetric heterofunctional ditopic ligand, 4-pyrazolecarboxylic acid, that exhibits an appropriate microporous structure for a thermodynamic-controlled separation of hydrocarbon isomers. This MOF produced via a direct, scalable, and mild synthesis route was proven to encompass a unique separation of C5/C6 isomers by classes of low RON over high RON alkanes with a sorption hierarchy: (n-hexane >> n-pentane approximate to 2-methylpentane>3-methylpentane)(low RON)>>(2,3-dimethylbutane approximate to i-pentane approximate to 2,2-dimethylbutane)(high RON) following the adsorption enthalpy sequence. We reveal for the first time that a single sorbent can efficiently separate such a complex mixture of high RON di-branched hexane and mono-branched pentane isomers from their low RON counterparts, which is a major achievement reported so far.

Keywords

Ultra-microporous metal-organic framework Isoreticular chemistry Pentane and hexane alkane isomers separation Octane upgrading of gasoline

URI

http://hdl.handle.net/10198/29765

Citation

Zhou, Lin; Brântuas, Pedro; Henrique, Adriano; Reinsch, Helge; Wahiduzzaman, Mohammad; Grenèche, Jean‐Marc; Rodrigues, Alírio E.; Silva, José A.C.; Maurin, Guillaume; Serre, Christian (2024). A microporous multi‐cage metal–organic framework for an effective one‐step separation of branched alkanes feeds. Angewandte Chemie-International Edition. ISSN 1433-7851. 63:15, p. 1-8