NL8403051A - Rhenium oxide contg. catalysts - on alumina-silica carrier, used with organo-tin co-catalyst for metathesis of functionalised olefin(s) - Google Patents

Abstract

A catalyst system for the metathesis of functionalised olefins comprises an aluminium oxide/silicon oxide carrier, rhenium oxide as catalyst component and an organotin cpd. as cocatalyst. The cocatalyst is pref. a tetraalkyltin cpd., esp. tetraethyltin and/or tetrabutyltin. Pref. the carrier comprises 5-95 (10-70) wt% Al2O3 and 5-95 (30-90) wt% SiO2.

Description

UU.U / Π * ƒ U1J1 * ί * 1 -¾ * * STAMICARBON B.V. (Licensing subsidiary of DSM) a

Inventors: Xiaoding Xu in Amsterdam Johannes C. Mol in Heiloo -1- PN 3581

CATALYST SYSTEM SUITABLE FOR THE METATHESIS OF FUNCTIONED OMLINATED OLEFINS

The invention relates to a catalyst system suitable for the metathesis of functionalized olefins.

Such catalyst systems are known, inter alia, from J. Organomet. Chem. 255 (1983) 159-171, R.H.A. Bosma et al., Heteroge-5 neous metathesis of unsaturated esters using a rhenium-based catalyst.

This article describes a catalyst system comprising an aluminum oxide support, rhenium oxide as the catalyst component, and a tin alkyl as a cocatalyst. French patent application 2,521,872 discloses catalyst systems manufactured by interaction of a tetraalkyl lead compound with a rhenium aluminate on an alumina or alumina / silica support.

These known catalyst systems exhibit reasonable activity at a high aluminum content while activity at low rhenium contents is only moderate. The object of the invention is a catalyst system with good activity and a rhenium content which, because of the high cost price of rhenium, is as low as possible.

Surprisingly, it has now been found that catalyst systems comprising alumina / silicon oxide as the support material, rheium oxide as the catalyst component and an organotin compound as the cocatalyst are more active than the previously known catalyst systems. This is all the more surprising because French patent application 2,521,872 teaches that when aluminum oxide is used as the support material, the use of a lead alkyl as a cocatalyst produces better results than when a tin alkyl is used.

A catalyst according to the invention is not only more active, but also considerably cheaper than the known catalysts, because of the low content of rhenium oxide required.

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Functionalized olefins are defined as olefins containing a functional group, having the general formula:

R] CH = CH (CH 2) n X

with R 1 = H or alkyl, X = a functional group, such as preferably 5 -COOR 3 or -CN, with R 2 and R 3 = alkyl, n> 1.

Metathesis of functionalized olefins is understood to mean self-metathesis or cometathesis with other olefins, whether or not functionalized.

Catalyst components are meant to mean compounds bonded to the support material. This can be accomplished, for example, by impregnating and calcining the solid support material with a solution of the catalyst component (s).

Cocatalysts, on the other hand, are not bound to the support material. They can be dosed separately and are in the reaction mixture during the reaction where, because of their influence on the conversion, they presumably interact with the support / catalyst component (s) and / or the substrate.

Organotin compounds can be used as cocatalyst, preferably SUB4, wherein R represents an alkyl. This alkyl can be methyl, ethyl or butyl, but also another compound. Preference is given to tetraethyltin and / or tetrabutyltin, as these provide the highest catalytic activity.

Catalysts of the invention exhibit the highest activity when the support material contains between 5 and 95 wt.% Alumina, based on the total weight of support material, and between 5 and 95 wt.% Silica. Preferably, the support material should contain at least 10 and at most 70 wt.% Alumina, in particular between 10 and 35 wt.

The invention will now be elucidated by means of a few examples: A. Preparation of the catalyst

10 g Si02.Al2C> 3 (250-500 μπι) with resp. 15.3 wt

Al2 O3 (Ketjen, LA, 144 m ^ / g) and 24.3 wt. Al2 O3 (Ketjen HA, -3- s · * 374 mfyg) was impregnated at 293 K with an aqueous solution of NH4 ReO4 as indicated in the table, column 4 «

This mixture was evaporated and dried at 383 K under air. For comparison, 10 g of γ-alumina (Ketjen, CK 100, 185-250 μτα, 195 5 g) was treated in the same manner.

Activation was effected by calcining the catalyst at 823 K for 4 hours, first 2 hours in a dry oxygen stream and then 2 hours in a dry nitrogen stream.

B. The Metathesis Reaction The metathesis reaction was carried out in a glass flask of about 30 ml content in which an argon atmosphere was maintained. To the flask were added successively with stirring: 100 mg of catalyst, 1 ml of solvent (n-hexane) containing 7.2 x 10 6 mol cocatalyst according to the table, column 3, and 250 μl (e.g. 10, 11 , 12 and 15 13) or 500 μΐ (e.g. 1 to 9) methyl oleate. The reaction was carried out at room temperature. The reaction products formed were 9-octadecene and dimethyl-9-octadecenedioate.

C. Analysis

The reaction was monitored by gas-liquid chromatography (GLC). The Ackman method was used to estimate the molecular response, (R.G. Ackman and J.C. Sipos, J. of Chromatography, 16, 1964, 298, and R.G. Ackman, J. of Gas Chromatography, 2, 1964, 173).

Reaction mixtures of esters were analyzed using a carbowax 20M or UCC-W-982 column. The reaction products were identified by comparison to the retention times of known samples.

The catalytic activity is expressed as the conversion after a 90 minute reaction time.

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TABLE

example carrier cocatalyst: g NH4 ReO4 / wt. % Re207 catalytic ____10 g carrier activity,% comp. 1 AI2O3 Sn (C2H5) 4 0.342 3 2 2 H.A. Sn (C2H5) 4 0.028 0.25 12 3 H.A. Sn (C2H5) 4 0.056 0.5 22 4 H.A. Sn (C2H5) 4 0.112 1 32 col. 5 AI2O3 Sn (C2H5) 4 2.431 18 36 6 H.A. Sn (C2H5) 4 0.226 2 38 7 H.A. Sn (C2H5) 4 0.342 3 42 8 H.A. Sn (C2H5) 4 0.707 6 45 col. 9 H.A. Pb (C2Hs) 4 0.342 3 23 col. 10 AI2O3 Sn (C2H5) 4 °> 342 3 5 11 L.A. Sa (C2H5) 4 0.342 3 16 12 H.A. Sn (C2H5) 4 0.342 3 52 col. 13 H.A. - 0.342 3 0 __; 1 f * 8403031

Claims (8)

Catalyst system suitable for the metathesis of functionalized olefins, comprising alumina / silica timoxide as the support material, rhenium oxide as the catalyst component, and an organotin compound as the cocatalyst. Catalyst system according to claim 1, wherein the support material contains between 5 and 95 wt.% Alumina, based on the total weight of support material, and between 5 and 95 wt.% Silica timoxide. Catalyst system according to claim 2, wherein the support material contains at least 10 and at most 70 wt.% Aluminum oxide, based on the total weight of support material. Catalyst system according to claims 1-3, wherein the organotin compound is a tetraalkyltin compound. Catalyst system according to claim 4, wherein the tetraalkyltin compound is tetraethyltin and / or tetrabutyltin. A method of metathetizing functionalized olefins using a catalyst system according to claims 1-5. The method of claim 6, wherein the functional group of the functionalized olefin is an ester. The method of claim 6, wherein the functional group of the functionalized olefin is a nitrile. 8403051