Center for Molecular Modeling - S. Couck

New Functionalized Metal–Organic Frameworks MIL-47-X (X = −Cl, −Br, −CH3, −CF3, −OH, −OCH3): Synthesis, Characterization, and CO2 Adsorption Properties

michel — Fri, 12 Jul 2013 14:14:55 +0000

S. Biswas, D.E.P. Vanpoucke, T. Verstraelen, M. Vandichel, S. Couck, K. Leus, Y-Y Liu, M. Waroquier, V. Van Speybroeck, J.F.M. Denayer, P. Van der Voort

Journal of Physical Chemistry C

117 (44), 22784–22796

2013

Abstract

Six new functionalized vanadium hydroxo terephthalates [VIII(OH)(BDC-X)]•n(guests) (MIL-47(VIII)-X-AS) (BDC = 1,4-benzenedicarboxylate; X = -Cl; -Br, -CH3, -CF3, -OH, -OCH3; AS = as-synthesized) along with the parent MIL-47 were synthesized under rapid microwave-assisted hydrothermal conditions (170 ºC, 30 min, 150 W). The unreacted H2BDC-X and/or occluded solvent molecules can be removed by thermal activation under vacuum leading to the empty-pore forms of the title compounds (MIL-47(VIV)-X). Except pristine MIL-47 (+III oxidation state), the vanadium atoms in all the evacuated functionalized solids stayed in +IV oxidation state. The phase purity of the compounds was ascertained by X-ray powder diffraction (XRPD), diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy, Raman, thermogravimetric (TG), and elemental analysis. The structural similarity of the filled and empty-pore forms of the functionalized compounds with the respective forms of parent MIL-47 was verified by cell parameter determination from XRPD data. TGA and temperature-dependent XRPD (TDXRPD) experiments in air atmosphere indicate high thermal stability in the range 330-385 ºC. All the thermally activated compounds exhibit significant microporosity (SLangmuir in the range 418-1104 m2 g-1), as verified by the N2 and CO2 sorption analysis. Among the six functionalized compounds, MIL-47(VIV)-OCH3 shows the highest CO2 uptake, demonstrating the determining role of functional groups on the CO2 sorption behaviour. For this compound and pristine MIL-47(VIV), Widom particle insertion simulations were performed based on ab initio calculated crystal structures. The theoretical Henry coefficients show a good agreement with the experimental values, and calculated isosurfaces for the local excess chemical potential indicate the enhanced CO2 affinity is due to two effects: (i) the interaction between the methoxy group and CO2 and (ii) the collapse of the MIL-47(VIV)-OCH3 framework.

DOI

http://dx.doi.org/10.1021/jp406835n

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14_JPhysChemC_117(44)22784_Biswas.pdf

New V-IV-Based Metal-Organic Framework Having Framework Flexibility and High CO2 Adsorption Capacity

mat — Thu, 22 Mar 2012 08:43:25 +0000

Y-Y Liu, S. Couck, M. Vandichel, M. Grzywa, K. Leus, S. Biswas, D. Volkmer, J. Gascon, F. Kapteijn, J.F.M. Denayer, M. Waroquier, V. Van Speybroeck, P. Van der Voort

Inorganic Chemistry

52 (1), 113-120

2013

Abstract

A vanadium based metal–organic framework (MOF), VO(BPDC) (BPDC2– = biphenyl-4,4′-dicarboxylate), adopting an expanded MIL-47 structure type, has been synthesized via solvothermal and microwave methods. Its structural and gas/vapor sorption properties have been studied. This compound displays a distinct breathing effect toward certain adsorptives at workable temperatures. The sorption isotherms of CO2 and CH4 indicate a different sorption behavior at specific temperatures. In situ synchrotron X-ray powder diffraction measurements and molecular simulations have been utilized to characterize the structural transition. The experimental measurements clearly suggest the existence of both narrow pore and large pore forms. A free energy profile along the pore angle was computationally determined for the empty host framework. Apart from a regular large pore and a regular narrow pore form, an overstretched narrow pore form has also been found. Additionally, a variety of spectroscopic techniques combined with N2 adsorption/desorption isotherms measured at 77 K demonstrate that the existence of the mixed oxidation states VIII/VIV in the titled MOF structure compared to pure VIV increases the difficulty in triggering the flexibility of the framework.

DOI

http://dx.doi.org/10.1021/ic301338a

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13_inorganic_chem_52(1)113_Liu.pdf

13_inorganic_chem_draft_Liu.pdf

Synthesis, characterization and sorption properties of NH2-MIL-47

mat — Thu, 22 Mar 2012 08:36:33 +0000

K. Leus, S. Couck, M. Vandichel, G. Vanhaelewyn, Y-Y Liu, G.B. Marin, I. Van Driessche, D. Depla, M. Waroquier, V. Van Speybroeck, J.F.M. Denayer, P. Van der Voort

Physical Chemistry Chemical Physics (PCCP)

14, 15562–15570

2012

Abstract

An amino functionalized vanadium-containing Metal Organic Framework, NH₂-MIL-47 has been synthesized by a hydrothermal reaction in an autoclave. Alternatively, a synthesis route via microwave enhanced irradiation has been optimized to accelerate the synthesis. The NH₂-MIL-47 exhibits the same topology as MIL-47, in which the V center is octahedrally coordinated. After an exchange procedure in DMF the V+III center is oxidized to V+IV, which is confirmed by EPR and XPS measurements. The CO² and CH₄ adsorption properties have been evaluated and compared to MIL-47, showing that both MOFs have an almost similar adsorption capacity and affinity for CO². DFT- based molecular modeling calculations were performed to obtain more insight into the adsorption positions for CO² in NH₂-MIL-47. Furthermore our calculated adsorption enthalpies agree well with the experimental values.

DOI

http://dx.doi.org/10.1039/C2CP42137B

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12 pccp 14,15562 Leus.pdf

Functionalized Metal-Organic Frameworks: MIL-47(V)+X : a computational investigation of its properties

wim — Thu, 26 Sep 2013 13:05:13 +0000

D.E.P. Vanpoucke, S. Biswas, T. Verstraelen, M. Vandichel, S. Couck, K. Leus, Y-Y Liu, M. Waroquier, V. Van Speybroeck, J.F.M. Denayer, P. Van der Voort

ISBN/ISSN: -

Poster

Conference / event / venue

Annual IAP Meeting

Ghent, Belgium

Wednesday, 18 September, 2013

Abstract (private)

IAP7_abstract_Vanpoucke.pdf

Conference reference

Annual IAP Meeting (2013)

A new series of V IV based metal-organic frameworks having framework flexibility and high CO2 adsorption capacity

bogaerts — Tue, 12 Feb 2013 07:01:41 +0000

Y-Y Liu, S. Couck, M. Vandichel, M. Grzywa, K. Leus, S. Biswas, D. Volkmer, J. Gascon, F. Kapteijn, J.F.M. Denayer, M. Waroquier, V. Van Speybroeck, P. Van der Voort

ISBN/ISSN:

Poster

Conference / event / venue

MOF2012

Edinburgh UK

Sunday, 16 September, 2012 to Wednesday, 19 September, 2012

Abstract (private)

2012-MOF2012-Liu.pdf

Synthesis, characterization, adsorption and catalytic properties of an amino functionalized Metal-Organic Framework: NH2-MIL-47

bogaerts — Tue, 12 Feb 2013 06:44:55 +0000

K. Leus, S. Couck, T. Bogaerts, M. Vandichel, Y-Y Liu, M. Waroquier, V. Van Speybroeck, J.F.M. Denayer, P. Van der Voort

ISBN/ISSN:

Poster

Conference / event / venue

MOF2012

Edinburgh UK

Sunday, 16 September, 2012 to Wednesday, 19 September, 2012

Abstract (private)

2012-MOF2012-Leus.pdf