Catalyst – solid sorbent – or support therefor: product or process – Catalyst or precursor therefor – Organic compound containing
Patent
1995-02-17
1997-04-15
Beck, Shrive
Catalyst, solid sorbent, or support therefor: product or process
Catalyst or precursor therefor
Organic compound containing
502150, 502155, 502158, 502167, 502168, 502242, 502247, 502248, 502254, 502255, 502305, 549523, 549525, 549533, B01J 3116, C07D30103
Patent
active
056209380
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
The invention relates to a catalyst for the epoxidation of alkenes using alkylhydroperoxide, the catalyst comprising an ion of one or more of the metals molybdenum, wolfram, titanium or vanadium on a solid inorganic carrier.
BACKGROUND OF THE INVENTION
Processes are known and practiced commercially for the epoxidation of olefins by catalytic reaction of alkenes with an alkylhydroperoxide. EP-A-193682, for instance, describes the use of molybdenum in a homogeneous catalysed reaction.
Efforts have been made by prior workers to develop heterogeneous catalyst systems useful in such epoxidations which are essentially insoluble in the reaction mixture. EP-A-421781 describes a molybdenum oxide on a solid silica carrier. Such a catalyst presents the drawback that the yield of the epoxidation reaction decreases if the same catalyst is used several times in succession. Furthermore, catalysts of this type are calcined. Calcination often causes sintering of the surface, which makes such a catalyst less readily regenerable. Furthermore, catalyst is lost in regeneration.
SUMMARY AND OBJECTS OF THE INVENTION
The invention provides a solution to these problems by providing a catalyst with which the metal (ion) is bound to the inorganic carrier via a polydentate organic ligand.
The catalyst according to the invention appears to combine a very high activity with a high selectivity in comparison with the catalyst described in EP-A-421781, and to be very stable as well.
The solid carrier is preferably an oxide of silicon, aluminium, titanium, or mixtures hereof; silicon oxide in particular is preferred because it is available in many types.
DETAILED DESCRIPTION OF THE INVENTION
The catalyst of the invention is useful for the epoxidation of alkenes using alkylhydroperoxide. The catalyst comprises an ion of at least one metal which is on a solid inorganic carrier wherein the metal ion is bound to the inorganic carrier by a polydentate organic ligand. The inorganic carrier has polydentate organic ligands to which a suitable selected metal ion is bound. By preference, the metal is molybdenum.
The polydentate ligand is preferably bi-, tri- or tetradentate. With particular preference use is made of di- or tridentate ligands. Higher-dentate ligands may shield the metal ion, which could make it less active.
The ligand preferably has oxygen, nitrogen or sulphur atoms as coordinating atoms for the metal ion. With more preference oxygen and/or nitrogen atoms are chosen. With particular preference the polydentate ligand has at least one coordinating nitrogen atom. The coordinating atoms are preferably in the form of an alcohol group, a ketone group, an aldehyde group, an ether group, a carboxyl group, a primary, secondary or tertiary amine group, an aromatic amine group or a sulphide group.
It is important for the catalyst according to the invention that the polyligand has a great stability with respect to the reaction medium, in this case the alkylhydroperoxide solution at a temperature of usually between 20.degree. and 200.degree. C. To this end it is preferable that the polydentate ligand contains no C.dbd.N (imine) or C.dbd.C (ethylenically unsaturated) groups.
Preferably the polydentate ligand is bound to a substrate via a siloxane group, the substrate being the inorganic solid carrier.
By preference, the carrier has groups as is shown in Formula (I): ##STR1## where: M=a metal chosen from the group comprising molybdenum, wolfram, titanium and vanadium; meaning of R.sup.3 ; COH, CNHR.sup.4 groups; R.sup.2 and Z having the meaning of X, aromatic) ring system.
Examples of suitable groups of polydentate ligands are salenes, bipyridines, diethylacetonates and quinolines.
Examples of polydentate ligands are: 2,2'-bipyridine, 1,10-phenanthroline, terpyridine, derivatives of salicylaldehyde, pyridinecarboxaldehyde and thiophene-aldehyde, such as salicylaldehyde-2-hydroxyanile, bisbis-(salicylaldehyde)ethylene diimine. The latter two compounds are preferably used in a hydrogenated form so that the imine funct
REFERENCES:
patent: 3726809 (1973-04-01), Allum et al.
patent: 3829392 (1974-08-01), Wulff
patent: 3980583 (1976-09-01), Mitchell et al.
patent: 4134906 (1979-01-01), Oswald et al.
patent: 4873212 (1989-10-01), Stapersma
patent: 5081267 (1992-01-01), Rameswaran et al.
patent: 5162279 (1992-11-01), Miki
patent: 5420313 (1995-05-01), Cumington et al.
patent: 5430161 (1995-07-01), Brown et al.
Beck Shrive
DSM N.V.
Meeks Timothy H.
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