REDUCIBLE POROUS CRYSTALLINE HYBRID SOLID FOR THE SEPARATION OF MIXTURES OF MOLECULES HAVING DIFFERENT DEGREES AND/OR A DIFFERENT NUMBER OF UNSATURATIONS

• US 20110172412A1
• Filed: 06/11/2009
• Published: 07/14/2011
• Est. Priority Date: 06/11/2008
• Status: Active Grant

• Current Assignee: Centre National De La Recherche Scientifique, Korea Research Institute of Chemical Technology
• Original Assignee: Centre National De La Recherche Scientifique, Université de Caen Basse-Normandie
• Inventors: Llewellyn, Philip, Daturi, Marco, Horcajada-Cortes, Patricia, Vimont, Alexandre, Chang, Jong-San, Serre, Christian, Ferey, Gérard, Hwang, Young-Kyu
• Granted Patent: US 8,926,736 B2
• Time in Patent Office: Days
• US Class Current: 540/145
• CPC Class Codes: C07C 11/06 Propene
• CPC Class Codes: C07C 7/13 by molecular-sieve technique
• CPC Class Codes: C07C 9/08 Propane
• CPC Class Codes: Y10S 95/90 Solid sorbent

Abstract

The present invention relates to reducible porous crystalline solids, constituted of a metal-organic framework (MOF), for the separation of mixtures of molecules having different unsaturation degrees and/or a different number of unsaturations with a selectivity that can be adjusted by controlling the reduction of the MOF.

The MOF solids of the present invention, after reduction, have a strong affinity for molecules containing at least one unsaturation. They can be used in various separation processes, especially those relating to hydrocarbons.

Claims

1. A porous crystalline MOF solid containing reduced metal sites for separating a mixture of molecules having different unsaturation degrees and/or a different number of unsaturations said solid containing a three-dimensional structure of moieties having the following formula (I)

M_mO_kX_lL_p 

 

(I)

in which;

each occurrence of M independently represents an ion of a transition metal M^z+ or the reduced form thereof M<sup>(z−

1)+</sup> selected from the group comprising Fe, Mn, Co, Ni and V, and in which z is 3 or 4, provided that the ratio y=M<sup>(z−

1)+</sup>/M^z+ lies between 0<

y≧

x, where x is the fraction of accessible ions M^z+ of the MOF solid,

m is 1 to 12,

k is 0 to 4,

l is 0 to 18,

p is 1 to 6,

X is an anion selected from the group comprising OH, Cl⁻

, F⁻

, I⁻

, Br⁻

, SO₄²⁻

, NO₃⁻

, ClO₄⁻

, PF₆⁻

, BF₄⁻

, R—

(COO)_n⁻

where R is as defined below, R¹—

(COO)_n⁻

, R¹—

(SO₃)_n⁻

and R¹—

(PO₃)_n⁻

, where R¹ is a hydrogen atom, a linear or branched, optionally substituted C₁ to C₁₂ alkyl or an optionally substituted C₆ to C₁₀ aryl, where n represents an integer from 1 to 4,

L is a spacer ligand comprising a radical R containing q carboxylate groups

2. The solid as claimed in claim 1, wherein the ligand L is a di-, tri-, tetra- or hexacarboxylate ligand selected from the group comprising:

C₂H₂ (CO₂⁻

)₂ (fumarate), C₂H₄ (CO₂⁻

)₂ (succinate), C₃H₆ (CO₂⁻

)₂ (glutarate), C₄H₄(CO₂⁻

)₂ (muconate), C₄H₈ (CO₂⁻

)₂ (adipate), C₅H₃S(CO₂⁻

)₂ (2,5-thiophenedicarboxylate), C₆H₄ (CO₂⁻

)₂ (terephthalate), C₆H₂N₂(CO₂⁻

)₂ (2,5-pyrazine dicarboxylate), C₇H₁₆ (CO₂⁻

)₂ (azelate), C₁₀H₆ (CO₂⁻

)₂ (naphthalene-2,6-dicarboxylate), C₁₂H₈ (CO₂⁻

) ₂ (biphenyl-4,4′

-dicarboxylate), C₁₂H₈N₂ (CO₂⁻

)₂ (azobenzenedicarboxylate), C₁₂H₆C₁₂N₂ (CO₂⁻

)₂ (dichloroazobenzenedicarboxylate), C₁₂H₆N₂ (CO₂⁻

) ₄ (azo-benzenetetracarboxylate), C₁₂H₆N₂ (OH)₂ (CO₂⁻

)₂ (dihydroxo-azobenzenedicarboxylate), C₆H₃ (CO₂⁻

) ₃ (benzene-1,2,4-tricarboxylate), C₆H₃ (CO₂⁻

) ₃ (benzene-1,3,5-tricarboxylate), C₂₄H₁₅(CO₂⁻

)₃ (benzene-1,3,5-tribenzoate), C₄₂H₂₇ (CO₂⁻

)₃ (1,3,5-tris[4′

-carboxy(1,1′

-biphenyl-4-yl)benzene), C₆H₂ (CO₂⁻

)₄ (benzene-1,2,4,5-tetracarboxylate, C₁₃H₄ (CO₂⁻

)₄ (naphthalene-2,3,6,7-tetracarboxylate), C₁₀H₄ (CO₂⁻

)₄ (naphthalene-1,4,5,8-tetracarboxylate), C₁₂H₆ (CO₂⁻

)₄ (biphenyl-3,5,3′

,5′

-tetracarboxylate, and the modified analogs selected from the group comprising 2-amino-terephthalate, 2-nitroterephthalate, 2-methyltere-phthalate, 2-chloroterephthalate, 2-bromoterephthalate, 2,5-dihydroxoterephthalate, 2,5-diperfluoroterephthalate, tetrafluoroterephthalate, 2,5-dicarboxyterephthalate, dimethyl-4,4′

-biphenyldicarboxylate, tetramethyl-4,4′

-biphenyldicarboxylate and dicarboxy-4,4′

-biphenyldicarboxylate.

3. The solid as claimed in claim 1, wherein the anion X is selected from the group comprising OH⁻

, Br⁻

, F⁻

, R—

(COO)_n⁻

, PF₆⁻

, NO₃⁻

, SO₄²⁻

and ClO₄⁻

, with R and n as defined in claim 1.

4. The solid as claimed in claim 1, wherein said mixture of molecules is selected from:

a mixture of at least one saturated hydrocarbon and at least one unsaturated hydrocarbon,

a mixture of at least one compound containing one or more free electron pair(s) and at least one compound not containing a free electron pair, and

a mixture of hydrogen (H₂) and carbon monoxide and/or dioxide.

5. The solid as claimed in claim 4, wherein the mixture of hydrocarbons is a mixture of propane and propene, a mixture of n-butane and isobutene, a mixture of n-butane and butenes, a mixture of acetylene and ethylene or a mixture of acetylene and carbon dioxide.

6. The solid as claimed in claim 1, wherein M is Fe, z is 3 and the ratio y=M^(z−

1)+/M^z+ lies between 0<

y≦

⅓

.

7. The solid as claimed in claim 1, wherein the MOF solid contains a three-dimensional succession of moieties having formula (I) selected from the group comprising:

M₃OX[C₆H₃ (CO₂)₃]₂ (structure of MIL-100 type)

M₃OX[C₆H₄ (CO₂)₂]₃ (structure of MIL-101 type)

M₃OX[C₆ (CH₃)₄ (CO₂)₂]₃ (structure of MIL-88B_—

4CH₃ type)

M₆O₂X₂[C₁₀H₂ (CO₂)₄]₃ (structure of MIL-102 type)

Fe₆O₂[C₁₂H₆N₂—

(CO₂)₄]₃.X₂.nH₂O (structure of MIL-127 type)

in which M is selected from Fe, Mn, Co, and X is as defined in claim 1.

8. The solid as claimed in claim 7, wherein M is Fe.

9. A process for separating a mixture of molecules having different unsaturation degrees and/or a different number of unsaturations by preferential adsorption of the molecules with a greater unsaturation degree and/or number of unsaturations on a porous crystalline MOF solid as defined in claim 1, wherein said process comprises at least one reaction step consisting

(i) in mixing in a polar solvent:

at least one solution containing at least one inorganic metal precursor present in the form of metal M, a metal salt of M or a coordination complex containing a metal ion of M,

at least one ligand L′

comprising a radical R containing q groups *—

C(═

O)—

R³, where

M, q and R are as defined in claim 1,

* designates the point of attachment of the group to the radical R,

R³ is selected from the group comprising an OH, an OY, wherein Y is an alkaline cation, a halogen, a radical —

OR⁴, —

O—

C(═

O)R⁴ or —

NR⁴R^4′

, where R⁴ and R^4′

are C_1-12 alkyl radicals,

to obtain an MOF material,

(ii) in activating the MOF material obtained in (i), and

(iii) in placing the MOF material obtained in step (ii) in contact with a mixture of molecules having different unsaturation degrees and/or a different number of unsaturations.

10. The process as claimed in claim 9, wherein step (ii) is a step of reduction of at least some of the metal centers M^z+ of said MOF material to M^(z−

1)+ ions in which z is 3.

11. The process as claimed in claim 9, wherein the activation step (ii) is performed at a temperature of 25 to 300°

C.

12. The process as claimed in claim 9, further comprising a step (i′

) of treatment of the MOF material obtained in step (i) with a source of F⁻

ions.

13. The process as claimed in claim 12, wherein the activation step (ii) is performed at a temperature of 50 to 250°

C.

14. The process as claimed in claim 9, wherein the mixture of molecules is selected from:

a mixture of at least one paraffin and at least one olefin.

a mixture of at least one olefin and one alkyne.

a mixture of acetylene and carbon dioxide.

a mixture of hydrogen (H₂) and carbon monoxide and/or dioxide.

15. The process as claimed in claim 14, wherein the mixture of molecules is a mixture of propane and propene, a mixture of n-butane and isobutene, a mixture of n-butane and butenes, a mixture of acetylene and ethylene, or a mixture of acetylene and carbon dioxide.

16. The process as claimed in claim 9, wherein the mixture of molecules is a mixture of at least one saturated hydrocarbon and at least one unsaturated hydrocarbon or carbon dioxide, and the Brø

nsted acidity of the MOF material obtained in step (ii) does not trigger polymerization of the unsaturated hydrocarbon.

17. The process as claimed in claim 9, wherein the mixture of molecules is in the gaseous phase.

18. The process as claimed in claim 9, further comprising a step (iv) of desorption of the molecule preferentially adsorbed.

19. The process as claimed in claim 18, wherein the desorption is effected by a desorption technique selected from displacement with an at least 98% pure gas at low pressure, a pressure change, a temperature change or a combination thereof.

20. (canceled)