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 catalyst comprising a vinylpyridine polymer and a titanium zeolite.
2. The catalyst of claim 1 wherein the titanium zeolite is encapsulated within the vinylpyridine polymer.
3. The catalyst of claim 2 wherein the titanium zeolite is TS-1.
4. The catalyst of claim 2 wherein the vinylpyridine polymer is a copolymer of a vinylpyridine and styrene.
5. The catalyst of claim 1 further comprising a transition metal.
6. The catalyst of claim 5 wherein the transition metal is palladium.
7. The catalyst of claim 1 comprising an admixture of the vinylpyridine polymer and the titanium zeolite.
8. The catalyst of claim 1 wherein the vinylpyridine polymer is crosslinked.
9. A process which comprises epoxidizing an olefin in the presence of hydrogen, oxygen, and the catalyst of claim 5 .
10. The process of claim 9 wherein the olefin is propylene and the transition metal is palladium.