Titanium zeolite catalysts
View Patent ↗Catalysts useful for epoxidizing olefins are disclosed. The catalysts comprise a vinylpyridine polymer and a titanium zeolite. Preferably, the vinylpyridine polymer encapsulates the titanium zeolite. The catalysts are easy to prepare and use, they are easy to recover and reuse, and they convert olefins to epoxides in good yields with high selectivity. Surprisingly, ring-opening reactions that form glycol or glycol ether by-products are minimized by using the vinylpyridine polymer-containing catalysts. The catalysts are valuable for making propylene oxide from propylene and hydrogen peroxide. Vinylpyridine polymer-encapsulated transition metals and their use to produce hydrogen peroxide from hydrogen and oxygen is also disclosed.
1. A process which comprises epoxidizing an olefin in the presence of a catalyst comprising a vinylpyridine polymer and a titanium zeolite.
2. The process of claim 1 wherein the olefin is propylene.
3. The process of claim 2 wherein the catalyst comprises a vinylpyridine polymer-encapsulated TS-1.
4. The process of claim 2 wherein the catalyst comprises an admixture of a vinylpyridine polymer and TS-1.
5. The process of claim 1 performed in the presence of a solvent selected from the group consisting of water, alcohols, and mixtures thereof.
6. A process which comprises epoxidizing propylene in the presence of hydrogen peroxide and a vinylpyridine polymer-encapsulated titanium zeolite in the presence of aqueous methanol at a temperature within the range of about 40° C. to about 80° C.
7. The process of claim 6 wherein the molar ratio of Propylene oxide to propylene oxide equivalent products is greater than 95%.
8. The process of claim 7 wherein the molar ratio of propylene oxide to propylene oxide equivalent products is greater than 98%.
9. A process which comprises epoxidizing propylene in the presence of hydrogen peroxide and an admixture of a crosslinked vinylpyridine polymer and a titanium zeolite in the presence of aqueous methanol at a temperature within the range of about 40° C. to about 80° C.
10. The process of claim 9 wherein the molar ratio of propylene oxide to propylene oxide equivalent products is greater than 95%.
11. A process which comprises reacting hydrogen and oxygen in a solvent in the presence of a catalyst comprising a vinylpyridine polymer-encapsulated transition metal to produce hydrogen peroxide.