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. A process comprising 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 silicon, said elements being incorporated into said matrix using at least one precursor comprising molybdenum and silicon, having at least one sequence of SiOMo bonds and a siloxy ligand, that is a molybdenum coordination complex containing a siloxy ligand, of 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 O, S or NR, the X groups, identical to or different from each other, are a halide, a substituted or unsubstituted alkyl, cycloalkyl or aryl, substituted or unsubstituted cyclopentadienyl group, or an alkoxy, aryloxy, siloxy, amide, hydrido, nitro, carboxylate, acetylacetonate, sulphonate, -diketiminate, iminopyrrolide, amidinate, thiocyanate or NR.sub.2CS.sub.2.sup. group, the R groups, identical to or different from each other, are a substituted or unsubstituted alkyl, cycloalkyl and aryl group, or a substituted or unsubstituted alkoxy and aryloxy group, the R groups, identical to or different from each other, are a substituted or unsubstituted alkyl, cycloalkyl and aryl group, m is equal to 1 or 2, n is 0 to 4, n is 0 to 2, z is 0 to 9, r is 0 to 2, and p is 1 to 10.

2. The process according to claim 1, wherein the X groups are F, Cl, Br, or I, and the R groups are substituted or unsubstituted alkyl, cycloalkyl and aryl groups having 1 to 10 carbon atoms.

3. The process according to claim 1, wherein the precursor is of 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, are substituted or unsubstituted alkyl, cycloalkyl and aryl groups or substituted or unsubstituted cycloalkyl and aryl groups, m is equal to 1 or 2, n is 0 to 2, and p is 1 to 10.

4. The process according to claim 1, wherein the precursor is of 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, are substituted or unsubstituted alkyl, cycloalkyl and aryl groups or substituted or unsubstituted alkoxy and aryloxy groups, m is equal to 1 or 2, n is 0 to 4, and p is 1 to 10.

5. The process according to claim 1, wherein the molybdenum coordination complex containing a siloxy ligand contains in its coordination sphere one or more optionally polydentate L-type ligands that are phosphorus-containing compounds, oxygen-containing compounds, nitrogen-containing compounds, nitrogen-containing aromatic compounds, and/or sulphur-containing compounds.

6. The process according to claim 1, wherein the precursor of molybdenum coordination complex type containing a siloxy ligand is MoO(OSiMe.sub.3)CN(CS.sub.2-NEt.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.

7. The process according to claim 1, wherein the mesoporous matrix is a matrix based on an oxide of at least one element X that is silicon, aluminium, titanium, zirconium, magnesium, lanthanum, cerium or mixtures thereof.

8. The process according to claim 1, wherein the catalyst is prepared by dry impregnation according to a process comprising: a) solubilization of the precursor comprising molybdenum and silicon and having at least one sequence of SiOMo bonds of formula I, 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 a), optional maturation of a solid thus obtained, c) optionally drying, calcination and/or steam treatment of the solid obtained at the end of b), at a temperature of 50 C. to 1000 C., and d) thermal activation of a solid obtained at the end of c), at a temperature range from 100 C. to 1000 C.

9. The process according to claim 1, wherein the catalyst is prepared according to a process comprising: a1) solubilization of the precursor comprising molybdenum and silicon and having at least one sequence of SiOMo bonds of formula I, and a precursor of the mesoporous matrix 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), c1) optionally drying, calcination and/or steam treatment of the solid particles obtained at the end of b1), and d1) thermal activation of the dry solid particles at the end of c1), at a temperature range from 100 to 1000 C.

10. The process according to claim 1, wherein metathesis is carried out at a temperature of 0 to 500 C.

11. The process according to claim 10, wherein metathesis is cross-metathesis reaction of ethylene with 2-butene, or a reverse reaction converting propylene to a mixture of ethylene and 2-butene.

12. The process according to claim 1, wherein the olefins are linear olefins of formula R.sup.1R.sup.2CCR.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 ring structure, the cyclic ring structure having 3 to 20 carbon atoms.

13. The process according to claim 3, wherein the catalyst is prepared by impregnation in excess solution according to the process comprising: a) solubilization of the precursor comprising molybdenum and silicon and having at least one sequence of SiOMo bonds, of formula (Ia), in a volume of solution corresponding to between 1.5 and 20 times 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 a), filtration and recovery of the solid, optional maturation of a solid thus obtained, c) optionally drying, calcination and/or steam treatment of the solid obtained at the end of b) at a temperature of 50 C. to 1000 C., and d) thermal activation of a solid obtained at the end of c) at a temperature of 100 C. to 1000 C.

14. The process according to claim 3, wherein the catalyst is prepared according to a process comprising: a1) solubilization of the precursor comprising molybdenum and silicon and having at least one sequence of SiOMo bonds of formula Ia, and a precursor of the mesoporous matrix 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 (Ia), c1) optionally drying, calcination and/or steam treatment of the solid particles obtained at the end of b1), and d1) thermal activation of the dry solid particles at the end of c1), at a temperature range from 100 to 1000 C.

15. The process according to claim 4, wherein the catalyst is prepared by impregnation in excess solution according to the process comprising: a) solubilization of the precursor comprising molybdenum and silicon and having at least one sequence of SiOMo bonds, of formula (Ib), in a volume of solution corresponding to between 1.5 and 20 times 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), filtration and recovery of the solid, optional maturation of a solid thus obtained, c) optionally drying, calcination and/or steam treatment of the solid obtained at the end of b) at a temperature of 50 C. to 1000 C., and d) thermal activation of a solid obtained at the end of c) at a temperature of 100 C. to 1000 C.

16. The process according to claim 4, wherein the catalyst is prepared according to a process comprising: a1) solubilization of the precursor comprising molybdenum and silicon and having at least one sequence of SiOMo bonds of formula Ib, and a precursor of the mesoporous matrix 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 (Ib), c1) optionally drying, calcination and/or steam treatment of the solid particles obtained at the end of b1), and d1) thermal activation of the dry solid particles at the end of c1), at a temperature range from 100 to 1000 C.

Description

BRIEF DESCRIPTION OF THE DRAWING

(1) FIG. 1 represents a graph of catalyst productivity of comparative catalysts and inventive catalysts.

EXAMPLES

(2) 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.

(3) 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

(4) 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

(5) 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

(6) 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

(7) 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)

(8) 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)

(9) 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

(10) 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 the FIGURE.

(11) 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.

(12) The stability of catalysts 1B to 1F according to the invention is better than the stability of catalyst 1A not according to the invention.