Ethylene oxide catalyst

Claim 2

A catalyst for the production of ethylene oxide by the controlled incomplete oxidation of ethylene with molecular oxygen which comprises a porous refractory support having deposited on its exterior and interior pore surfaces metallic silver and compounds of thallium wherein the silver ranges from about 1 percent to about 25 percent by weight and the thallium concentration ranges from about 0.5×10 -3 to about 1.5×10 -3 gram atomic weight per kilogram (gaw/kg) of total catalyst.

Claim 3

The catalyst of claim 1 wherein the silver ranges from about 2 to about 20 percent by weight.

Claim 4

The catalyst of claim 2 wherein the silver ranges from about 4 to about 16 percent by weight.

Claim 5

The catalyst of claim 1 wherein the surface area of the support ranges from about 0.03 to about 5 square meters per gram (m 2 /g).

Claim 6

The catalyst of claim 4 wherein the surface area of the support ranges from about 0.05 to about 3 m 2 /g.

Claim 7

The catalyst of claim 1 wherein the support comprises alpha alumina.

Claim 8

The catalyst of claim 1 wherein the support comprises siliceous material.

Claim 9

A catalyst for the production of ethylene oxide by the controlled incomplete oxidation of ethylene with molecular oxygen consisting essentially of a porous alpha alumina support having a surface area of from about 0.03 m 2 /g to about 5 m 2 /g and having deposited on its exterior and pore surfaces from about 1 to about 25 percent by weight of silver and from about 0.5×10 -3 to about 1.5×10 -3 gaw/kg of total catalyst of thallium.

Claim 10

A catalyst for the production of ethylene oxide by the controlled incomplete oxidation of ethylene with molecular oxygen consisting essentially of a porous alpha alumina support having a surface area of from about 0.03 m 2 /g to about 5 m 2 /g and having deposited on its exterior and pore surfaces from about 1 to about 25 percent by weight of silver and from about 0.5×10 -3 to about 1.5×10 -3 gaw/kg of total catalyst of thallium.

Claim 11

The catalyst of claim 8 wherein the silver ranges from about 2 to about 20 percent by weight.

Claim 12

The catalyst of claim 8 wherein the surface area of the support ranges from about 0.05 to about 3 m 2 /g.

Claim 13

A process for preparing a catalyst for the production of ethylene oxide by the controlled incomplete oxidation of ethylene with molecular oxygen which comprises: (a) contacting a porous refractory support having a surface area from about 0.03 to about 5 m 2 /g with a liquid phase having dissolved therein a thallium salt- or mixtures of thallium salts in an amount sufficient to deposit from about 0.5×10 -3 to about 1.5×10 -3 gaw/kg of total catalyst of thallium, (b) at least partially drying this impregnated support sufficiently to allow the impregnation of step (c), (c) recontacting the thallium impregnated support with a liquid phase containing dissolved therein a silver compound in an amount sufficient to deposit from about 1 to about 25 percent by weight of silver on the support surface, and, (d) thermally treating the resulting product in the presence of a reducing agent in order to convert the silver compound to silver.

Claim 14

A process for preparing a catalyst for the production of ethylene oxide by the controlled incomplete oxidation of ethylene with molecular oxygen which comprises: (a) contacting a porous refractory support having a surface area from about 0.03 to about 5 m 2 /g with a liquid phase having dissolved therein a thallium salt- or mixtures of thallium salts in an amount sufficient to deposit from about 0.5×10 -3 to about 1.5×10 -3 gaw/kg of total catalyst of thallium, (b) at least partially drying this impregnated support sufficiently to allow the impregnation of step (c), (c) recontacting the thallium impregnated support with a liquid phase containing dissolved therein a silver compound in an amount sufficient to deposit from about 1 to about 25 percent by weight of silver on the support surface, and, (d) thermally treating the resulting product in the presence of a reducing agent in order to convert the silver compound to silver.

Claim 15

The process of claim 11 wherein the silver deposited ranges from about 2 to about 20 percent by weight.

Claim 16

The process of claim 12 wherein the silver deposited ranges from about 4 to about 16 percent by weight.

Claim 17

The process of claim 11 wherein the surface area of the support ranges from about 0.5 to about 3 m 2 /g.

Claim 18

The process of claim 11 wherein the support comprises alpha alumina.

Claim 19

A catalyst prepared by the process of claim 11.

Claim 20

A process for preparing a catalyst for the production of ethylene oxide by the controlled incomplete oxidation of ethylene with molecular oxygen which comprises: (a) contacting a porous refractory support having a surface area from about 0.03 to about 5 m 2 /g with a liquid phase having dissolved therein a silver compound sufficient to deposit on the support from about 1 to about 25 percent by weight of silver and thallium salt or salts sufficient to deposit on the support from about 0.5×10 -3 to about 1.5×10 -3 gaw/kg of total catalyst of thallium thereby depositing silver compounds and thallium salts on the support, and, (b) thermally treating the resulting product in the presence of a reducing agent to convert the silver compound to silver metal.

Claim 21

A process for preparing a catalyst for the production of ethylene oxide by the controlled incomplete oxidation of ethylene with molecular oxygen which comprises: (a) contacting a porous refractory support having a surface area from about 0.03 to about 5 m 2 /g with a liquid phase having dissolved therein a silver compound sufficient to deposit on the support from about 1 to about 25 percent by weight of silver and thallium salt or salts sufficient to deposit on the support from about 0.5×10 -3 to about 1.5×10 -3 gaw/kg of total catalyst of thallium thereby depositing silver compounds and thallium salts on the support, and, (b) thermally treating the resulting product in the presence of a reducing agent to convert the silver compound to silver metal.

Claim 22

The process of claim 17 wherein the silver deposited ranges from about 2 to about 20 percent by weight.

Claim 23

The process of claim 18 wherein the silver deposited ranges from about 4 to about 16 percent by weight.

Claim 24

The process of claim 17 wherein the surface area of the support ranges from about 0.05 to about 3 m 2 /g.

Claim 25

The process of claim 17 wherein the support comprises alpha alumina.

Claim 26

A catalyst prepared by the process of claim 17.

Claim 27

A process for preparing a catalyst for the production of ethylene oxide by the controlled incomplete oxidation of ethylene with molecular oxygen which comprises: (a) contacting a porous refractory support having a surface area from about 0.03 to about 5 m 2 /g with a liquid phase have dissolved therein a silver compound sufficient to deposit on the support from about 1 to about 25 percent by weight of silver, (b) thermally treating the resulting product in the presence of a reducing agent in order to convert the silver compound to silver, (c) recontacting the silver-metal impregnated support with a liquid phase having dissolved therein a thallium salt or mixtures of thallium salts sufficient to deposit on the support from about 0.5×10 -3 to about 1.5×10 -3 gaw/kg of total catalyst of thallium, (d) drying the resulting catalyst to produce the finished catalyst.

Claim 28

A process for preparing a catalyst for the production of ethylene oxide by the controlled incomplete oxidation of ethylene with molecular oxygen which comprises: (a) contacting a porous refractory support having a surface area from about 0.03 to about 5 m 2 /g with a liquid phase have dissolved therein a silver compound sufficient to deposit on the support from about 1 to about 25 percent by weight of silver, (b) thermally treating the resulting product in the presence of a reducing agent in order to convert the silver compound to silver, (c) recontacting the silver-metal impregnated support with a liquid phase having dissolved therein a thallium salt or mixtures of thallium salts sufficient to deposit on the support from about 0.5×10 -3 to about 1.5×10 -3 gaw/kg of total catalyst of thallium, (d) drying the resulting catalyst to produce the finished catalyst.

Claim 29

The process of claim 23 wherein the silver deposited ranges from about 2 to about 20 percent by weight.

Claim 30

The process of claim 24 wherein the silver deposited ranges from about 4 to about 16 percent by weight.

Claim 31

The process of claim 23 wherein the surface area of the support ranges from about 0.05 to about 3 m 2 /g.

Claim 32

The process of claim 23 wherein the support comprises alpha aluminum.

Claim 33

A catalyst article prepared by the process of claim 23.