Direct epoxidation catalyst and process
View Patent ↗A catalyst comprising a transition metal zeolite, a noble metal, and a thiol is disclosed. The catalyst is used in an epoxidation process comprising reacting an olefin, hydrogen, and oxygen. The presence of a thiol in the catalyst reduces the formation of alkanes from the hydrogenation of olefins, and/or improves hydrogen and oxygen selectivities to epoxides.
1. A catalyst comprising a transition metal zeolite, palladium, and a thiol, wherein the thiol is tethered to the transition metal zeolite.
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 further comprising gold.
5. A catalyst comprising a transition metal zeolite, palladium, a thiol, and a binder, wherein the thiol is tethered to the binder.
6. An epoxidatibn process comprising reacting an olefin, hydrogen, and oxygen in the presence of a catalyst comprising a transition metal zeolite, palladium, and a thiol.
7. The process of claim 6 wherein the transition metal zeolite is a titanium zeolite.
8. The process of claim 6 wherein the transition metal zeolite is TS-1.
9. The process of claim 6 wherein the catalyst further comprises gold.
10. The process of claim 6 performed in the presence of a solvent.
11. The process of claim 10 wherein the solvent is an oxygenated solvent.
12. The process of claim 11 wherein the solvent is selected from the group consisting of water, methanol, ethanol, isopropanol, tert-butanol, and mixtures thereof.
13. The process of claim 6 performed in the presence of a buffer.
14. The process of claim 13 wherein the buffer is an ammonium phosphate.
15. The process of claim 6 wherein the olefin is propylene.