Catalysts for the production of ethylene oxide

• US 5,011,807 A
• Filed: 08/29/1989
• Issued: 04/30/1991
• Est. Priority Date: 08/30/1988
• Status: Expired due to Term

• Current Assignee: Dow Technology Investments LLC (Dow, Inc.)
• Original Assignee: Imperial Chemical Industries PLC (IMPERIAL CHEMICAL INDUSTRIES)
• Inventors: Hayden, Percy, Pinnegar, Harry
• Primary Examiner(s): KONOPKA, PAUL
• Application Number:
  US07/400,133
• Time in Patent Office: 609 Days
• Field of Search: 502/218, 502/216, 502/219, 502/220, 502/317, 502/348
• US Class Current: 502/218
• CPC Class Codes: B01J 23/50 Silver
• CPC Class Codes: B01J 23/683 with chromium, molybdenum or tungsten
• CPC Class Codes: C07D 301/10 with catalysts containing silver or gold
• CPC Class Codes: Y02P 20/52 using catalysts, e.g. selective catalysts

Abstract

Catalysts of attractive activities for use in the oxidation of ethylene to ethylene oxide comprise silver supported on a porous heat resisting support, a group VI A transition metal, potassium, rubidium and/or cesium and sulphur.

Claims

1. A catalyst for the production of ethylene oxide by the oxidation of ethylene with oxygen which consists essentially of silver supported on a porous heat resisting support, a group VI A transition metal selected from the group consisting of chromium, molybdenum and tungsten, an alkali metal selected from potassium, rubidium and cesium, and sulphur, said catalyst including 3 to 50% by weight of silver and 0.1 to 5 gram atoms of the transition metal, 0.1 to 10 gram atoms of sulphur and 0.1 to 15 gram atoms of the alkali metal per million grams of catalyst.

2. A catalyst as claimed in claim 1 in which the sulphur is in the form of sulfate ions.

3. A catalyst as claimed in claim 1 in which the alkali metal is cesium.

4. A catalyst as claimed in claim 2 in which the support has a surface area of 0.05 to 10 m² /g and a pore volume of 0.2 to 0.9 ml/g.

5. A catalyst as claimed in claim 4 in which the support is α

-alumina.

6. A process of producing a catalyst as claimed in claim 1 in which silver is introduced to the preformed porous heat resisting support by impregnation with a solution of a silver compound and decomposing the compound to silver by heating the impregnated support to a temperature of 100 to 700°

C.

7. A process as claimed in claim 5 wherein the solution of the silver compound comprises ammonia and/or a nitrogen containing base, the alkali metal, the transition metal and a compound of sulphur which is a sulfate or a compound of sulphur which forms a sulfate during production of the catalyst or in its subsequent use, and wherein the silver compound is decomposed to silver by heating at a temperature of 100 to 550°

C.