Catalyst for producing alkylene oxide, method for producing the same, and method for producing alkylene oxide using said catalyst

• US 8,017,546 B2
• Filed: 09/13/2007
• Issued: 09/13/2011
• Est. Priority Date: 09/15/2006
• Status: Expired due to Fees

• Current Assignee: Nippon Shokubai Company Limited
• Original Assignee: Nippon Shokubai Company Limited
• Inventors: Hirota, Hiroyuki, Mikawa, Masatsugu, Shima, Masahide, Sento, Tadashi
• Primary Examiner(s): OH, TAYLOR V
• Application Number:
  US12/311,000
• Publication Number:
  US 20090259059A1
• Time in Patent Office: 1,461 Days
• Field of Search: 549/534, 502/243, 502/347, 502/348
• US Class Current: 502/243
• CPC Class Codes: B01J 21/04 Alumina
• CPC Class Codes: B01J 23/50 Silver
• CPC Class Codes: B01J 23/66 Silver or gold
• CPC Class Codes: B01J 23/688 with manganese, technetium or rhenium
• CPC Class Codes: B01J 35/393 Metal or metal oxide crystallite size
• CPC Class Codes: B01J 35/612 less than 10 m2/g
• CPC Class Codes: B01J 35/633 less than 0.5 ml/g
• CPC Class Codes: B01J 35/635 0.5-1.0 ml/g
• CPC Class Codes: B01J 37/346 of microwave energy
• CPC Class Codes: C07D 301/10 with catalysts containing silver or gold
• CPC Class Codes: C07D 303/02 Compounds containing oxirane rings

Abstract

A catalyst for producing alkylene oxide including fine metal silver particles dispersed and supported on a carrier, wherein not less than 90% of the fine metal silver particles have silver particle diameters of 2 to 100 nm, is disclosed. The catalyst can be produced by impregnating a carrier with a liquid containing a silver compound or a silver ion; drying the carrier; and then irradiating the carrier with microwave to form fine metal silver particles in dispersed state on the carrier. This catalyst is used for producing olefin oxide by contact gas-phase oxidation of olefin by a molecular-oxygen-containing gas.

Claims

1. A catalyst for producing alkylene oxide comprising fine metal silver particles dispersed and supported on a carrier, wherein not less than 90% of said fine metal silver particles have a silver particle diameter of 2 to 100 nm, wherein an average diameter of said fine metal silver particles is 30 to 100 nm, and wherein a water absorption rate of the carrier is 20 to 60%.

2. The catalyst according to claim 1, wherein said carrier is an α

-alumina carrier.

3. The catalyst according to claim 1, wherein said carrier comprises silicon oxide in an amount of 0.1 to 5% by mass.

4. The catalyst according to claim 1, wherein a supported amount of said fine metal silver particles is 3 to 40 mass % based on a mass of the carrier.

5. The catalyst according to claim 1, wherein a supported amount of said fine metal silver particles is 3 to 25 mass % based on a mass of the carrier, and not less than 90% of the fine metal silver particles has a silver particle diameter in a range of 20 to 80 nm.

6. The catalyst according to claim 1, wherein particle diameters of said fine metal silver particles are in a range of 30 nm less than the average particle diameter to 30 nm greater than the average particle diameter.

7. The catalyst according to claim 1, wherein a BET specific surface area of said carrier is 0.1 to 5.0 m²/g.

8. The catalyst according to claim 1, wherein said carrier comprises an alkali metal element.

9. The catalyst according to claim 1, wherein said catalyst comprises at least one element selected from the group consisting of alkali metals and rhenium as a promoter.

10. The catalyst according to claim 1, wherein a water absorption rate with respect to a mass of said carrier is 20 to 60 mass %.

14. A method for producing alkylene oxide comprising conducting a step of gas-phase oxidation of an olefin by a molecular-oxygen-containing gas in the presence of the catalyst according to claim 1.

15. The method for producing alkylene oxide according to claim 14, wherein said olefin is ethylene.

11. A method for producing a catalyst for producing alkylene oxide comprising:

impregnating a carrier with a liquid containing a silver compound or a silver ion;

drying the carrier; and

then irradiating the carrier with microwave to form fine metal silver particles on the carrier.

12. The method according to claim 11, wherein the solution containing a silver compound or a silver ion further contains an amine compound.

13. The method according to claim 11, wherein the carrier after being irradiated with microwave is treated at a temperature in a range of 400 to 950°

C. in an inert gas.