Epoxidation process using a mixed catalyst system
The invention is a process for epoxidizing olefins with hydrogen and oxygen in the presence of a palladium-containing titanium zeolite and a palladium-free titanium zeolite. The process exhibits good productivity and selectivity for olefin epoxidation with hydrogen, and oxygen. Surprisingly, the presence of palladium-free titanium zeolite in addition to the palladium-containing titanium zeolite in the process improves the palladium productivity of the process.
1 . A process for producing an epoxide comprising reacting an olefin, hydrogen and oxygen in the presence of a catalyst mixture comprising a palladium-containing titanium zeolite and a palladium-free titanium zeolite.
2 . The process of claim 1 wherein the palladium-containing titanium zeolite comprises palladium and a titanium silicalite.
3 . The process of claim 2 wherein the titanium silicalite is TS-1.
4 . The process of claim 1 wherein the palladium-containing titanium zeolite comprises palladium, a titanium zeolite, and a noble metal selected from the group consisting of platinum, gold, silver, iridium, rhenium, ruthenium, osmium, and mixtures thereof.
5 . The process of claim 4 wherein the noble metal is selected from the group consisting of platinum, gold, and mixtures thereof.
6 . The process of claim 1 wherein the palladium-containing titanium zeolite comprises from about 0.01 to about 10 weight percent palladium.
7 . The process of claim 1 wherein the palladium-free titanium zeolite is a titanium silicalite.
8 . The process of claim 1 wherein the palladium-free titanium zeolite is TS-1.
9 . The process of claim 1 wherein the olefin is a C 2 -C 6 olefin.
10 . The process of claim 1 wherein the olefin is propylene.
11 . The process of claim 1 wherein reaction of olefin, hydrogen and oxygen is performed in a solvent.
12 . The process of claim 11 wherein the solvent is selected from the group consisting of water, C 1 -C 4 alcohols, supercritical CO 2 , and mixtures thereof.
13 . The process of claim 11 wherein the solvent contains a buffer.
14 . A process comprising reacting propylene, hydrogen and oxygen in a solvent in the presence of a catalyst mixture comprising a palladium-containing titanium silicalite and palladium-free TS-1, wherein the palladium-containing titanium silicalite comprises palladium and a titanium silicalite.
15 . The process of claim 14 wherein the titanium silicalite is TS-1.
16 . The process of claim 14 wherein the palladium-containing titanium zeolite further comprises a noble metal selected from the group consisting of platinum, gold, silver, iridium, rhenium, ruthenium, osmium, and mixtures thereof.
17 . The process of claim 14 wherein the solvent is selected from the group consisting of water, C 1 -C 4 alcohols, supercritical CO 2 , and mixtures thereof.
18 . The process of claim 14 wherein the solvent contains a buffer.
19 . (canceled)
20 . (canceled)