OLEFIN METATHESIS METHOD USING A CATALYST CONTAINING ALUMINIUM AND MOLYBDENUM INCORPORATED BY MEANS OF AT LEAST TWO PRECURSORS

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 aluminium, said elements being incorporated into said matrix by means of at least two precursors of which at least one precursor contains molybdenum and at least one precursor contains aluminium.

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 two precursors of which at least one precursor contains molybdenum and at least one precursor contains aluminium.

2. Process according to claim 1 in which the molybdenum-containing precursor is a precursor of the coordination complex type based on molybdenum and/or of the polyoxometallate type based on molybdenum and/or of the (thio)molybdate type.

3. Process according to claim 1 in which the molybdenum-containing precursor of the coordination complex type based on molybdenum corresponds to formula (I)
Mo.sub.m(Y).sub.n(N).sub.n.(X).sub.o(CR.sub.2).sub.r (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, chlorate, bromate, iodate, nitrate, sulphate or hydrogen sulphate, alkylsulphate, thiosulphate, carbonate or hydrogen carbonate, phosphate or hydrogen phosphate or dihydrogen phosphate, the substituted or unsubstituted alkyl, cycloalkyl or aryl, substituted or unsubstituted cyclopentadienyl groups, the alkoxy, aryloxy, siloxy, amide, hydrido, nitro, carboxylate, acetylacetonate, sulphonate, -diketiminate, iminopyrrolure, amidinate, borate, cyanide, cyanate, thiocyanate or NR.sub.2CS.sub.2.sup. groups, the R and R groups, identical to or different from each other, are selected from the alkyl and aryl groups, preferably comprising between 1 and 10 carbon atoms, the alkoxy and aryloxy groups, m is equal to 1 or 2, n is comprised between 0 and 4, n is comprised between 0 and 2, o is comprised between 0 and 10, r is comprised between 0 and 2, n+n+o+r is greater than or equal to 1.

4. Process according to claim 1 in which the molybdenum-containing precursor of the polyoxometallate type based on molybdenum corresponds to formula (II)
(X.sub.xMo.sub.mM.sub.bO.sub.yH.sub.h).sup.q.nH.sub.2O (II) in which, x is greater than or equal to 0, m is greater than or equal to 2, b is greater than or equal to 0, y is greater than or equal to 7, h is comprised between 0 and 12, q is comprised between 1 and 20, n is comprised between 0 and 200, x, m, b, y, h, n and q being integers, X being an element selected from phosphorus, silicon and boron, M being a metallic element selected from aluminium, zinc, nickel, cobalt, tungsten, vanadium, niobium, tantalum, iron and copper.

5. Process according to claim 4 in which the precursor of the polyoxometallate type based on molybdenum is an isopolyanion based on molybdenum in which the subscript x of the element X is equal to 0.

6. Process according to claim 4 in which the precursor of the polyoxometallate type based on molybdenum is a heteropolyanion selected from the group formed by the Strandberg heteropolyanion of formula X.sub.2Mo.sub.5O.sub.23H.sub.h.sup.q.nH.sub.2O, the Anderson heteropolyanion of formula XMo.sub.6O.sub.24H.sub.h.sup.q.nH.sub.2O, the Keggin heteropolyanion of formula XMo.sub.12O.sub.40H.sub.h.sup.q.nH.sub.2O, a lacunary Keggin heteropolyanion of formula XMo.sub.11O.sub.39H.sub.h.sup.q.nH.sub.2O, the lacunary Keggin heteropolyanion of formula XMo.sub.9O.sub.34H.sub.h.sup.q.nH.sub.2O, the Dawson heteropolyanion of formula X.sub.2Mo.sub.18O.sub.62H.sub.h.sup.q.nH.sub.2O, the Preyssler heteropolyanion of formula X.sub.5Mo.sub.30O.sub.110H.sub.h.sup.q.nH.sub.2O with X, h and q having the definitions according to claim 4.

7. Process according to claim 4 in which the precursor of the polyoxometallate type based on molybdenum is a heteropolyanion selected from the group formed by the Strandberg heteropolyanion of formula X.sub.2Mo.sub.4CoO.sub.23H.sub.h.sup.q.nH.sub.2O, the Anderson heteropolyanion of formula XMo.sub.5CoO.sub.24H.sub.h.sup.q.nH.sub.2O, the Keggin heteropolyanion of formula XMo.sub.11CoO.sub.40H.sub.h.sup.q.nH.sub.2O, a lacunary Keggin heteropolyanion of formula XMo.sub.10CoO.sub.39H.sub.h.sup.q.nH.sub.2O, the lacunary Keggin heteropolyanion of formula XMo.sub.8CoO.sub.34H.sub.h.sup.q.nH.sub.2O, the Dawson heteropolyanion of formula X.sub.2Mo.sub.17CoO.sub.62H.sub.h.sup.q.nH.sub.2O, the Preyssler heteropolyanion of formula X.sub.5Mo.sub.29CoO.sub.110H.sub.h.sup.q.nH.sub.2O with X, h and q having the definitions according to claim 4.

8. Process according to claim 1 in which the molybdenum-containing precursor of the (thio)molybdate type corresponds to formula (III)
C.sub.c(MoY.sub.4).sub.z (III) in which C represents an organic or inorganic cation, such as the protons, ammoniums, phosphoniums, alkalis, alkaline-earths, transition elements, the Y groups, identical to or different from each other, can be selected from O and S, c is comprised between 1 and 4, z is comprised between 1 and 10.

9. Process according to claim 1 in which the aluminium-containing precursor is selected from the precursors of the coordination complex type based on aluminium and/or the precursors of the aluminium salt type and/or the precursors of the heteropolyanion salt type based on aluminium and/or any colloidal solution of alumina.

10. Process according to claim 1 in which the aluminium-containing precursor of the coordination complex type based on aluminium corresponds to formula (IV)
Al.sub.nR.sub.m.xH.sub.2O (IV) in which, n is comprised between 1 and 3, m is comprised between 1 and 3, x is comprised between 0 and 200, the R groups identical to or different from each other, are selected from hydrogen, the halides, such as F, Cl, Br, I, chlorate, bromate, iodate, nitrate, sulphate or hydrogen sulphate, alkylsulphate, thiosulphate, carbonate or hydrogen carbonate, phosphate or hydrogen phosphate or dihydrogen phosphate, the substituted or unsubstituted alkyl, alkenyl, alkynyl, cycloalkyl or aryl, substituted or unsubstituted cyclopentadienyl groups, the hydroxy, alkoxy, aryloxy, carboxylate, nitrate, acetylacetonate, sulphonate, perchlorate groups.

11. Process according to claim 1 in which the aluminium-containing precursor of the aluminium salt type corresponds to formula (V)
[Al.sub.nR.sub.m].sup.[C].sup.+.nH.sub.2O (V) in which, n is comprised between 1 and 3, m is comprised between 1 and 3, x is comprised between 0 and 200, the R groups identical to or different from each other, can be selected from hydrogen, the oxo group, the halides, such as F, Cl, Br, I, the substituted or unsubstituted alkyl, alkenyl, alkynyl, cycloalkyl or aryl, substituted or unsubstituted cyclopentadienyl groups, the hydroxy, alkoxy, aryloxy, carboxylate, sulphonate, nitrate, acetylacetonate, perchlorate groups, C is selected from hydrogen, the alkali, alkaline-earth elements, transition metals, post-transition metals and rare earths, the ammonium and phosphonium cations.

12. Process according to claim 1 in which the aluminium-containing precursor of the heteropolyanion salt type based on aluminium corresponds to formula (VI)
(Al.sub.aM1.sub.mM2.sub.bX.sub.xO.sub.yH.sub.h).sup.q(C.sup.r+).sub.c.nH.sub.2O (VI) in which, a is greater than or equal to 0, m is greater than or equal to 1, b is greater than or equal to 0, x is greater than or equal to 0, y is greater than or equal to 10, h is comprised between 0 and 12, q is comprised between 0 and 20, r is comprised between 0 and 20, c is comprised between 0 and 20, n is comprised between 0 and 200, x, m, y, h, n and q being integers, X being an element selected from phosphorus, silicon and boron, M1 and M2, identical to or different from each other, being metallic elements selected from aluminium, zinc, nickel, cobalt, molybdenum, tungsten, vanadium, niobium, tantalum, iron and copper, C represents one or more atoms, identical or different, hydrated or non-hydrated, selected from the elements of the periodic table capable of existing in the cationic form, such as hydrogen, the alkali, alkaline-earth elements, transition metals, post-transition metals and rare earths, in hydrated or non-hydrated forms, selected from the oxygen-containing and/or nitrogen-containing and/or phosphorus-containing organic cations, such as the ammoniums and phosphoniums.

13. 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, titanium, zirconium, magnesium, lanthanum, cerium and mixtures thereof.

14. 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 molybdenum-containing precursor and the aluminium-containing precursor 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.

15. 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 molybdenum-containing precursor 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) drying stage intended to remove the impregnation solvent from solution a), d) solubilization of the aluminium-containing precursor in a volume of solution corresponding to the pore volume of the solid obtained in stage c), e) impregnation of the solid obtained in stage c) with the solution obtained in stage d), optional maturation of the solid thus obtained, f) optional stage of drying, calcination and/or steam treatment of the solid obtained at the end of stage e), 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., g) stage of thermal activation of the solid obtained at the end of stage f), 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.

16. 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 molybdenum-containing precursor and the aluminium-containing precursor in a volume of solution, preferably aqueous, 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.

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

18. Process according to claim 17 in which the olefins are linear olefins corresponding to general 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 structure, the ring comprising from 3 to 20 carbon atoms.

19. Process according to claim 1 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

[0143] In the examples, the molybdenum-containing precursor of the heteropolyanion type PMo.sub.12O.sub.40H.sub.3 and the precursors containing aluminium of the coordination complex type Al.sub.2(SO.sub.4).sub.3 are commercially available.

Example 1A (Not According to the Invention)

Preparation of 6.7%Mo/SiO.SUB.2 .by Dry Impregnation with a Solution of PMo.SUB.12.O.SUB.40..SUP.3..3H.SUP.+..30H.SUB.2.O

[0144] 1.5 g of PMo.sub.12O.sub.40.sup.3.3H.sup.+.30H.sub.2O is dissolved at 60 C. in 11.7 ml of distilled water. On complete dissolution, a silica (S.sub.BET=462 m.sup.2/g, V.sub.p=0.75 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 6.4%Mo+1%Al/SiO.SUB.2 .by Dry Impregnation with a Solution of PMo.SUB.12.O.SUB.40..SUP.3..3H.SUP.+..30H.SUB.2.O_and Al.SUB.2.(SO.SUB.4.).SUB.3..18H.SUB.2.O

[0145] 1.5 g of PMo.sub.12O.sub.40.sup.3.3H.sup.+.30H.sub.2O and 1.83 g of Al.sub.2(SO.sub.4).sub.3.18H.sub.2O are dissolved at 60 C. in 11.7 ml of distilled water. On complete dissolution, a silica (S.sub.BET=462 m.sup.2/g, V.sub.p=0.75 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

[0146] 2 g of catalyst prepared in Example 1A and 1B 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.

[0147] The activity of the catalyst 1B according to the invention prepared by impregnation with a molybdenum-containing precursor and an aluminium-containing precursor is greater than the activity of catalyst 1A not according to the invention and prepared by impregnation with a single molybdenum-containing precursor.

[0148] The stability of catalyst 1B according to the invention is better than the stability of catalyst 1A not according to the invention.