Catalyst system for producing ketones from epoxides

1. A catalyst composition, comprising:

at least one precious metal; and

at least one mixed oxide;

wherein the mixed oxide comprises zirconium dioxide and silicon dioxide;

wherein the precious metal is supported and the support is not entirely made of the mixed oxide; and

wherein a mass ratio of zirconium dioxide to silicon dioxide in the mixed oxide is 86:14 to 99.9:0.1.

2. The catalyst composition according to claim 1 , wherein the support does not comprise the mixed oxide.

3. The catalyst composition according to claim 1 , wherein the support of the precious metal is selected from the group consisting of silicon dioxide, aluminum oxide and mixtures thereof.

4. The catalyst composition according to claim 1 , wherein the precious metal is selected from the group consisting of ruthenium, rhodium, palladium, osmium, iridium, platinum and mixtures thereof.

5. The catalyst composition according to claim 1 , wherein the precious metal is palladium.

6. A process for producing a catalyst composition according to claim 1 , comprising:

a) preparing a mouldable mass which at least comprises

i. a zirconium compound,

ii. silicon dioxide as solid, and

iii. water, and

b) calcining the mouldable mass at a temperature of from 300 to 500° C. to prepare the mixed oxide.

7. The process according to claim 6 , wherein the precious metal is impregnated on an inert support to produce the catalyst system.

8. The process according to claim 6 ,

wherein the catalyst composition comprises at least one precious metal and at least one mixed oxide,

wherein the mixed oxide comprises zirconium dioxide and silicon dioxide,

wherein the specific surface area of the mixed oxide, measured according to BET methods, is 5-155 m 2 /g,

wherein the precious metal is supported on the mixed oxide,

wherein the mixed oxide has a monomodal pore radius distribution, and

wherein the mass ratio of zirconium dioxide to silicon dioxide in the mixed oxide is 86:14 to 99.9:0.1,

wherein,

a) a mouldable mass is prepared which at least comprises

i. a zirconium compound,

ii. silicon dioxide as solid having a particle size d 50 , as measured by laser diffraction, of at least 100 nm,

iii. water, and

b) the mouldable mass is calcined at a temperature of from 300 to 500° C. to prepare the mixed oxide.

9. The process according to claim 8 , wherein the precious metal is impregnated on the mixed oxide as support.

10. The process according to claim 6 , wherein the particle size d 50 , as measured by laser diffraction, of the silicon dioxide is 100 nm to 500 μm.

11. The process according to claim 6 , wherein the zirconium compound is selected from the group consisting of zirconium dioxide, zirconium hydroxide, zirconium acetate, zirconium nitrate, zirconium oxychloride, ammonium zirconium carbonate and mixtures thereof.

12. The process according to claim 6 , wherein the zirconium compound is selected from the group consisting of zirconium dioxide, zirconium hydroxide and mixtures thereof.

13. The process according to claim 6 , wherein the zirconium compound is a mixture of A and B, wherein

A is selected from the group consisting of zirconium dioxide, zirconium hydroxide and mixtures thereof; and

B is selected from the group consisting of zirconium acetate, zirconium nitrate, zirconium oxychloride, ammonium zirconium carbonate and mixtures thereof.

14. The process according to one of claim 6 , wherein the mouldable mass is reshaped to give mouldings prior to the calcination.

15. A process for producing a ketone, comprising:

reacting a compound containing at least one epoxide group in the presence of a catalyst composition;

wherein the catalyst composition comprises at least one precious metal and at least one mixed oxide, wherein the mixed oxide comprises zirconium dioxide and silicon dioxide, wherein the precious metal is supported on a support and wherein a mass ratio of zirconium dioxide to silicon dioxide in the mixed oxide is 86:14 to 99.9:0.1, and wherein the support is the mixed oxide or the support does not consist of the mixed oxide.

16. The process according to claim 15 , wherein the ketone is cyclododecanone.

17. A process for the synthesis of a lactam, comprising:

producing a ketone according to claim 15 and reacting said ketone to produce said lactam.