Speaker
Description
MIL-101(Cr) is one of the metal organic frameworks (MOFs) that has been successfully applied to gas/solute separation1 and catalysis2 because of its large specific surface area, pore accessibility and noticeable chemical and solvent stability.1 It has been modified in many studies to enhance its efficiency for customized applications. The modifications range from combination with other nanomaterials to functionalization and metal doping. In this work, we apply several density functional theory (DFT) methods including the B3LYP, M06-L, M06-2X, PBE, PW91 and ωB97X-D functionals in the framework of localized-orbital calculations (using the Gaussian 16 package3) to model functionalization of this MOF by three different organophosphorus compounds in toluene, and the adsorption of several metal ions in an aqueous solution. The functionalization was devised to promote the efficiency and selectivity of MIL-101(Cr) in separation of some heavy rare earth ions from multicomponent aqueous solutions.4 However, the uncertainty about the mechanism of metal ion recovery by the modified MOF and the preference of the heavy rare earth ions motivated modeling of the synthesis and metal recovery process. To this end, the thermodynamics parameters are analyzed to predict which organophosphorus compound and metal ion have the highest potential of incorporation into/complexation with the modified MOF. Furthermore, the computational challenges are discussed including downsizing of the 12756-atom unit cell to a computationally affordable model, spin state, structural stability, geometry symmetry breaking and spin contamination.
References:
(1) C.-X. Yang et al., Analytical chemistry 83, 2011, 7144-7150.
(2) X. Cao et al., Dalton Transactions 2021. DOI: 10.1039/D0DT04048G
(3) M. J. Frisch et al., Gaussian Inc., Wallingford CT, 2016.
(4) V. Kavun et al., Microporous and Mesoporous Materials 312, 2021, 110747.
| Speaker Country | Finland |
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