Direct epoxidation process
View Patent ↗A catalyst comprising a transition metal zeolite and a noble metal is disclosed. The catalyst is prepared by an extrusion method using a comb-branched polymer as an extrusion aid. The catalyst is used in a reaction to produce epoxide from an olefin, hydrogen, and oxygen. The comb-branched polymer improves the mechanical properties of the extrudate.
1. A catalyst comprising a transition metal zeolite and a noble metal, wherein the catalyst is prepared by an extrusion method using a comb-branched polymer as an extrusion aid.
2. The catalyst of claim 1 wherein the transition metal zeolite is a titanium zeolite.
3. The catalyst of claim 1 wherein the transition metal zeolite is TS-1.
4. The catalyst of claim 1 wherein the comb-branched polymer comprises recurring units of an ethylenic carboxylic monomer and a polyether macromonomer.
5. The catalyst of claim 4 wherein the ethylenic carboxylic monomer is an acrylic monomer.
6. The catalyst of claim 1 wherein the noble metal is selected from the group consisting of gold, silver, platinum, palladium, iridium, ruthenium, osmium, and mixtures thereof.
7. The catalyst of claim 1 further comprising an inorganic oxide.
8. The catalyst of claim 7 wherein the inorganic oxide is a titania.
9. A method for preparing the catalyst of claim 7 , comprising
a. extruding a mixture comprising the transition metal zeolite, the noble metal, the inorganic oxide, and the comb-branched polymer to produce a polymer-containing extrudate, wherein the noble metal is supported on the inorganic oxide;
b. calcining the polymer-containing extrudate in an oxygen-containing atmosphere.
10. The method of claim 9 wherein the mixture further comprises a solvent.
11. A method for preparing the catalyst of claim 1 , comprising
a. extruding a mixture comprising the noble metal, the transition metal zeolite, and the comb-branched polymer to produce a polymer-containing extrudate; and
b. calcining the polymer-containing extrudate in an oxygen-containing atmosphere.
12. The method of claim 11 wherein the mixture further comprises a solvent.
13. The method of claim 11 wherein the noble metal is supported on the transition metal zeolite.
14. The method of claim 13 wherein the mixture further comprises a solvent.
15. A method for preparing the catalyst of claim 1 , comprising
a. extruding a mixture comprising the transition metal zeolite and the comb-branched polymer to produce a polymer-containing extrudate;
b. calcining the polymer-containing extrudate in an oxygen-containing atmosphere to produce a calcined extrudate; and
c. supporting the noble metal on the calcined extrudate.
16. The method of claim 15 wherein the mixture further comprises a solvent.
17. An epoxidation process comprising reacting an olefin, hydrogen, and oxygen in the presence of the catalyst of claim 1 .
18. The process of claim 17 wherein the olefin is propylene.
19. The process of claim 17 wherein the catalyst is in a fixed bed.
20. The process of claim 17 wherein the transition metal zeolite is TS-1.
21. The process of claim 17 wherein the catalyst is prepared by a method comprising
a. extruding a mixture comprising the noble metal, the transition metal zeolite, and the comb-branched polymer to produce a polymer-containing extrudate, wherein the noble metal is supported on the transition metal zeolite; and
b. calcining the polymer-containing extrudate in an oxygen-containing atmosphere.
22. The process of claim 17 wherein the catalyst is prepared by a method comprising
a. extruding a mixture comprising the transition metal zeolite, the noble metal, the comb-branched polymer, and an inorganic oxide to produce a polymer-containing extrudates, wherein the noble metal is supported on the inorganic oxide; and
b. calcining the polymer-containing extrudate in an oxygen-containing atmosphere.
23. The process of claim 17 wherein the catalyst is prepared by a method comprising
a. extruding a mixture comprising the transition metal zeolite and the comb-branched polymer to produce a polymer-containing extrudate;
b. calcining the polymer-containing extrudate in an oxygen-containing atmosphere to produce a calcined extrudate; and
c. supporting the noble metal on the calcined extrudate.