OLEFIN METATHESIS METHOD USING A CATALYST CONTAINING SILICON AND MOLYBDENUM

Abstract

The invention relates to a process for the metathesis of olefins implemented with a catalyst comprising a mesoporous matrix and at least the elements molybdenum and silicon, said elements being incorporated into said matrix by means of at least one precursor comprising molybdenum and silicon and having at least one sequence of SiOMo bonds.

Claims

1. Process for the metathesis of olefins carried out by bringing the olefins into contact with a catalyst comprising a mesoporous matrix and at least the elements molybdenum and aluminium, said elements being incorporated into said matrix using at least one precursor comprising molybdenum and silicon and having at least one sequence of SiOMo bonds.

2. Process according to claim 1 in which the precursor is a molybdenum coordination complex containing a siloxy ligand and comprising at least one sequence of SiOMo bonds and/or a precursor of heteropolyanion type based on molybdenum containing at least one sequence of SiOMo bonds.

3. Process according to claim 1 in which when the precursor is a molybdenum coordination complex containing a siloxy ligand, it corresponds to formula (I)
Mo.sub.m(?Y).sub.n(?N).sub.n(X).sub.z(?CR.sub.2).sub.r(OSiR.sub.3).sub.p(I) in which the Y groups, identical to or different from each other, are selected from O, S and NR, the X groups, identical to or different from each other, are selected from the halides, such as F, Cl, Br, I, the substituted or unsubstituted alkyl, cycloalkyl or aryl, substituted or unsubstituted cyclopentadienyl groups, the alkoxy, aryloxy, siloxy, amide, hydrido, nitro, carboxylate, acetylacetonate, sulphonate, ?-diketiminate, iminopyrrolide, amidinate, thiocyanate or NR.sub.2CS.sub.2.sup.? group s, the R groups, identical to or different from each other, are selected from the substituted or unsubstituted alkyl, cycloalkyl and aryl groups, preferably comprising between 1 and 10 carbon atoms, or from the substituted or unsubstituted alkoxy and aryloxy groups, the R groups, identical to or different from each other, are selected from the substituted or unsubstituted alkyl, cycloalkyl and aryl groups, m is equal to 1 or 2, n is comprised between 0 and 4, n is comprised between 0 and 2, z is comprised between 0 and 9, r is comprised between 0 and 2, p is comprised between 1 and 10.

4. Process according to claim 2, in which when the precursor is a precursor of molybdenum coordination complex type containing a siloxy ligand, it corresponds to formula (Ia):
Mo.sub.m(?N).sub.n(OSiR.sub.3).sub.p(Ia) in which the R groups, identical to or different from each other, can be selected from the substituted or unsubstituted alkyl, cycloalkyl and aryl groups, preferably comprising between 1 and 10 carbon atoms, or from the substituted or unsubstituted cycloalkyl and aryl groups, m is equal to 1 or 2, n is comprised between 0 and 2, p is comprised between 1 and 10.

5. Process according to claim 2 in which when the precursor is a precursor of molybdenum coordination complex type containing a siloxy ligand, it corresponds to formula (Ib)
Mo.sub.m(?O).sub.n(OSiR.sub.3).sub.p(Ib) in which the R groups, identical to or different from each other, can be selected from the substituted or unsubstituted alkyl, cycloalkyl and aryl groups, preferably comprising between 1 and 10 carbon atoms, or from the substituted or unsubstituted alkoxy and aryloxy groups, m is equal to 1 or 2, n is comprised between 0 and 4, p is comprised between 1 and 10.

6. Process according to claim 2 in which the molybdenum coordination complex containing a siloxy ligand contains in its coordination sphere one or more L-type ligands, optionally polydentate selected from the phosphorus-containing compounds, the oxygen-containing compounds, the nitrogen-containing compounds, the nitrogen-containing aromatic compounds, and/or the sulphur-containing compounds such as the thioethers.

7. Process according to claim 2 in which the precursor of molybdenum coordination complex type containing a siloxy ligand is selected from the following compounds: MoO(OSiMe.sub.3)CN(CS.sub.2NEt.sub.2).sub.2, Mo(?N-(2,6-di-iPrC.sub.6H.sub.3))(tBu)(?CHtBu)(OSi(OtBu).sub.3), Mo(?S)(?NiPr)(OSitBu.sub.3).sub.2, Mo(?O)(OSitBu.sub.3).sub.4, Mo(?N)(OSiPh.sub.3).sub.3(C.sub.6H.sub.5N) or Mo.sub.2(OSiMe.sub.3).sub.6.

8. Process according to claim 1 in which when the precursor according to the invention is a precursor of heteropolyanion type, it corresponds to formula (II):
(Si.sub.xMo.sub.mM.sub.bO.sub.yH.sub.h).sup.q?.nH.sub.2O(II) in which, x is equal to 1 or 2, m is greater than or equal to 1, b is greater than or equal to 0, m+b greater than or equal to 5, y is comprised between 20 and 50, h is comprised between 0 and 12, q is comprised between 3 and 12, n is comprised between 0 and 200; x, m, b, y, h, n and q being integers, M being a metallic element selected from aluminium, zinc, nickel, cobalt, tungsten, vanadium, niobium, tantalum, iron and copper.

9. Process according to claim 8 in which the precursor of heteropolyanion type based on molybdenum is selected from the group formed by a Strandberg heteropolyanion of formula Si.sub.2Mo.sub.5O.sub.23.sup.8?.nH.sub.2O, an Anderson heteropolyanion of formula SiMo.sub.6O.sub.24.sup.8?.nH.sub.2O, a Keggin heteropolyanion of formula SiMo.sub.12O.sub.40.sup.4?.nH.sub.2O, a lacunary Keggin heteropolyanion of formula SiMo.sub.11O.sub.39.sup.8?.nH.sub.2O, a lacunary Keggin heteropolyanion of formula SiMo.sub.9O.sub.34.sup.10?.nH.sub.2O, a Dawson heteropolyanion of formula Si.sub.2Mo.sub.18O.sub.62.sup.8?.nH.sub.2O, a Preyssler heteropolyanion of formula Si.sub.5Mo.sub.30O.sub.110.sup.20?.nH.sub.2O.

10. Process according to claim 8 in which the precursor of heteropolyanion type based on molybdenum is selected from the group formed by a Strandberg heteropolyanion of formula Si.sub.2Mo.sub.4CoO.sub.23.sup.12?.nH.sub.2O, an Anderson heteropolyanion of formula SiMo.sub.5CoO.sub.24.sup.12?.nH.sub.2O, a Keggin heteropolyanion of formula SiMo.sub.11CoO.sub.40.sup.8?.nH.sub.2O, a lacunary Keggin heteropolyanion of formula SiMo.sub.10CoO.sub.39.sup.12?.nH.sub.2O, a lacunary Keggin heteropolyanion of formula SiMo.sub.8CoO.sub.34.sup.14?.nH.sub.2O, a Dawson heteropolyanion of formula Si.sub.2Mo.sub.17CoO.sub.62.sup.12?.nH.sub.2O, a Preyssler heteropolyanion of formula Si.sub.5Mo.sub.29CoO.sub.110.sup.24?.nH.sub.2O.

11. Process according to claim 1 in which the mesoporous matrix is a matrix based on the oxide of at least one element X selected from silicon, aluminium, titanium, zirconium, magnesium, lanthanum, cerium and mixtures thereof.

12. Process according to claim 1 in which the catalyst is prepared by dry impregnation according to the process comprising the following stages: a) solubilization of the precursor comprising molybdenum and silicon and having at least one sequence of SiOMo bonds, in a volume of solution corresponding to the pore volume of a preformed mesoporous matrix based on oxide, b) impregnation of the preformed mesoporous matrix based on oxide with the solution obtained in stage a), optional maturation of the solid thus obtained, c) optional stage of drying, calcination and/or steam treatment of the solid obtained at the end of stage b), at a pressure greater than or equal to 0.1 MPa or less than or equal to 0.1 MPa, in a temperature range from 50? C. to 1000? C., d) stage of thermal activation of the solid obtained at the end of stage c), at a pressure greater than or equal to 0.1 MPa or less than or equal to 0.1 MPa, in a temperature range from 100? C. to 1000? C.

13. Process according to claim 1 in which the catalyst is prepared by impregnation in excess according to the process comprising the following stages: a) solubilization of the precursor comprising molybdenum and silicon and having at least one sequence of SiOMo bonds, of formula (I), (Ia), or (Ib), and/or of formula (II) in a volume of solution corresponding to between 1.5 and 20 times the pore volume of the preformed mesoporous matrix based on oxide, b) impregnation of the preformed mesoporous matrix based on oxide, with the solution obtained in stage a), filtration and recovery of the solid, optional maturation of the solid thus obtained, c) optional stage of drying, calcination and/or steam treatment of the solid obtained at the end of stage b) at a pressure greater than or equal to 0.1 MPa or less than or equal to 0.1 MPa, in a temperature range from 50? C. to 1000? C., d) stage of thermal activation of the solid obtained at the end of stage c) at a pressure greater than or equal to 0.1 MPa or less than or equal to 0.1 MPa, in a temperature range from 100? C. to 1000? C.

14. Process according to claim 1 in which the catalyst is prepared according to the process comprising the following stages: a1) solubilization of the precursor comprising molybdenum and silicon and having at least one sequence of SiOMo bonds, and precursors of the mesoporous matrix based on oxide of at least one element X in an aqueous or hydro-organic solution in the presence of a pore-forming agent so as to form a colloidal solution, b1) spray-drying said colloidal solution so as to obtain spherical solid elemental particles incorporating the mesostructured matrix based on oxide and the precursor comprising molybdenum and silicon and having at least one sequence of SiOMo bonds, of formula (I), (Ia), or (Ib), and/or of formula (II), c1) optional stage of drying, calcination and/or steam treatment of the solid particles obtained at the end of stage b1) at a pressure greater than or equal to 0.1 MPa or less than or equal to 0.1 MPa, d1) stage of thermal activation of the dry solid particles at the end of stage c1), at a pressure greater than or equal to 1 bar or less than or equal to 0.1 MPa, in a temperature range from 100 to 1000? C.

15. Process according to claim 1 in which the metathesis reaction is carried out at a temperature comprised between 0 and 500? C.

16. Process according to claim 1 in which the olefins are linear olefins corresponding to general formula R.sup.1R.sup.2C?CR.sup.3R.sup.4, where R.sup.1, R.sup.2, R.sup.3 and R.sup.4, identical or different, are hydrogen or a hydrocarbyl radical of 1 to 20 carbon atoms, or olefins with a cyclic structure, the ring comprising from 3 to 20 carbon atoms.

17. Process according to claim 15 in which the metathesis reaction is the cross-metathesis reaction of ethylene with 2-butene, or the reverse reaction converting propylene to a mixture of ethylene and 2-butene.

Description

EXAMPLES

[0140] In the examples, the precursor of complex coordination type containing a siloxy ligand, tris(triphenylsilyloxy)molybdenum nitride stabilized with pyridine Mo(?N)(OSiPh.sub.3).sub.3(Pyridine) and the precursors of heteropolyanion type phosphomolybdic acid PMo.sub.12O.sub.40.sup.3?.3H.sup.+ and silicomolybdic acid SiMo.sub.12O.sub.40.sup.4?.4H.sup.+ are commercially available.

[0141] The heteropolyanion precursor cobaltosilicomolybdic acid SiCoMo.sub.11O.sub.40.sup.4?.4H.sup.+ is synthetized according to a method described in patent application FR 2,764,211.

Example 1A (Not According to the Invention): Preparation of 6.7%Mo/Al.SUB.2.O.SUB.3 .by Dry Impregnation with a Solution with PMo.SUB.12.O.SUB.40..SUP.3?..3H.SUP.+..30H.SUB.2.O

[0142] 1.5 g of PMo.sub.12O.sub.40.sup.3?.3H.sup.+.30H.sub.2O is dissolved at 60? C. in 7.3 ml of distilled water. On complete dissolution, an alumina (S.sub.BET=198 m.sup.2/g, V.sub.p=0.47 ml/g) is impregnated with this solution. The solid obtained is matured for 24 h at 25? C. under air. The resulting solid is dried in an oven at 120? C. for 24 h then activated under nitrogen at 550? C. for 2 h.

Example 1B (According to the Invention): Preparation of 6.7%Mo/Al.SUB.2.O.SUB.3 .by Dry Impregnationtion with SiMo.SUB.12.O.SUB.40..SUP.4?..4H.SUP.+..28H.SUB.2.O

[0143] 1.4 g of SiMo.sub.12O.sub.40.sup.4?.4H.sup.+.28H.sub.2O is dissolved at 60? C. in 7.3 ml of distilled water. On complete dissolution, an alumina (S.sub.BET=198 m.sup.2/g, V.sub.p=0.47 ml/g) is impregnated with this solution. The solid obtained is matured for 24 h at 25? C. under air. The resulting solid is dried in an oven at 120? C. for 24 h then activated under nitrogen at 550? C. for 2 h.

Example 1C (According to the Invention): Preparation of 6.1%Mo+0.3%Co/Al.SUB.2.O.SUB.3 .by Dry Impregnation with a Solution of SiCoMo.SUB.11.O.SUB.40..SUP.4?..4H.SUP.+..28H.SUB.2.O

[0144] 1.4 g of SiCoMo.sub.11O.sub.40.sup.4?.4H.sup.+.28H.sub.2O is dissolved at 60? C. in 7.3 ml of distilled water. An alumina (S.sub.BET=198 m.sup.2/g, V.sub.p=0.47 ml/g) is impregnated with this solution. The solid obtained is matured for 24 h at 25? C. under air. The resulting solid is dried in an oven at 120? C. for 24 h then activated under nitrogen at 550? C. for 2 h.

Example 1D (According to the Invention): Preparation of 6.7%Mo+0.9%Co/Al.SUB.2.O.SUB.3 .by Dry Impregnation with a Solution of SiMo.SUB.12.O.SUB.40..SUP.4?..4H.SUP.+..28H.SUB.2.O and of Co(NO.SUB.3.).SUB.2

[0145] 1.4 g of SiMo.sub.12O.sub.40.sup.4?.4H.sup.+.28H.sub.2O and 0.69 g of Co(NO.sub.3).sub.2.6H.sub.2O are dissolved at 60? C. in 7.3 ml of distilled water. An alumina (S.sub.BET=198 m.sup.2/g, V.sub.p=0.47 ml/g) is impregnated with this solution. The solid obtained is matured for 24 h at 25? C. under air. The resulting solid is dried in an oven at 120? C. for 24 h then activated under nitrogen at 550? C. for 2 h.

Example 1E (According to the Invention): Preparation of 6.7%Mo/Al.SUB.2.O.SUB.3 .by Dry Impregnation with a Solution of Mo(?N)(OSiPh.SUB.3.).SUB.3.(Pyridine)

[0146] 11.6 g of Mo(?N)(OSiPh.sub.3).sub.3(Pyridine) is dissolved at 60? C. in 7.3 ml of distilled water. An alumina (S.sub.BET=198 m.sup.2/g, V.sub.p=0.47 ml/g) is impregnated with this solution. The solid obtained is matured for 24 h at 25? C. under air. The resulting solid is dried in an oven at 120? C. for 24 h then activated under nitrogen at 550? C. for 2 h.

Example 1F (According to the Invention): Preparation of 6.7%Mo/Al.SUB.2.O.SUB.3 .by Dry Impregnation with a Solution of SiMo.SUB.12.O.SUB.40..SUP.4?..4H.SUP.+..28H.SUB.2.O and of Mo(?N)(OSiPh.SUB.3.).SUB.3.(Pyridine)

[0147] 0.7 g of SiMo.sub.12O.sub.40.sup.4?.4H.sup.+.28H.sub.2O and 5.8 g of Mo(?N)(OSiPh.sub.3).sub.3(Pyridine) are dissolved at 60? C. in 7.3 ml of distilled water. An alumina (S.sub.BET=198 m.sup.2/g, V.sub.p=0.47 ml/g) is impregnated with this solution. The solid obtained is matured for 24 h at 25? C. under air. The resulting solid is dried in an oven at 120? C. for 24 h then activated under nitrogen at 550? C. for 2 h.

Example 2: Metathesis of Propylene to Ethylene and 2-Butene

[0148] 2 g of catalyst prepared in Example 1A to 1F is mixed in a proportion of 50% by weight with silicon carbide (SiC) in a double-jacketed fixed bed reactor. The heat transfer fluid of the double jacket is heated to 70? C. Pure propylene is conveyed to the reactor by means of a Gilson pump and the pressure is set at 4.5 MPa. The productivity of the catalysts expressed in millimole of propylene consumed per gram of catalyst and per hour is quantified as a function of time denoted t (in hours denoted h) in FIG. 1.

[0149] The activity of all the catalysts 1B to 1F according to the invention prepared by impregnation with precursors based on molybdenum having SiOMo bonds is greater than the activity of catalyst 1A not according to the invention and prepared by impregnation with a precursor based on molybdenum not having SiOMo bonds: PMo.sub.12O.sub.40.sup.3?.3H.sup.+.30H.sub.2O.

[0150] The stability of catalysts 1B to 1F according to the invention is better than the stability of catalyst 1A not according to the invention.