Exhaust gas purifying catalyst and production method thereof

Patent metadata

Field	Value
Publication number	US-2016184804-A1
Application number	US-201514962697-A
Country	US
Kind code	A1
Filing date	Dec 8, 2015
Priority date	Dec 26, 2014
Publication date	Jun 30, 2016
Grant date	—

Abstract

An exhaust gas purifying catalyst has enhanced NOx purification performance in a lean atmosphere, and a production method for producing an exhaust gas purifying catalyst includes sputtering a target material containing Ta and Rh to form composite fine metal particles respectively containing Ta and Rh.

First claim

1 . A method for producing an exhaust gas purifying catalyst, comprising sputtering a target material containing Ta and Rh to form composite fine metal particles respectively containing Ta and Rh.

2 . The method according to claim 1 , further comprising loading the composite fine metal particles on powdered supports.

3 . The method according to claim 1 , wherein the target material is a micromixed target material obtained by mixing powdered Ta and Rh, and molding and sintering the mixture.

4 . An exhaust gas purifying catalyst having a plurality of composite fine metal particles respectively containing Ta and Rh, wherein the average particle diameter of the composite fine metal particles is 100 nm or less.

5 . The exhaust gas purifying catalyst according to claim 4 , further having powdered supports, wherein the composite fine metal particles are loaded on the powdered supports.

6 . The exhaust gas purifying catalyst according to claim 5 , wherein the powdered support is a powdered support selected from the group consisting of SiO 2 , ZrO 2 , CeO 2 , Al 2 O 3 , TiO 2 or a combination thereof.

7 . The exhaust gas purifying catalyst according to claim 4 , wherein the each content percentage of Ta in 70% or more on a number basis of the composite fine metal particles is from 20 to 200% of the average content percentage of Ta in a plurality of the composite fine metal particles.

8 . The exhaust gas purifying catalyst according to claim 4 , wherein the each particle diameter of 70% or more on a number basis of the composite fine metal particles is from 60 to 140% of the average particle diameter of a plurality of the composite fine metal particles.

9 . The exhaust gas purifying catalyst according to claim 4 , which is a catalyst for purifying NOx.

10 . An exhaust gas purifying method comprising bringing an NOx-containing exhaust gas into contact with the exhaust gas purifying catalyst according to claim 9 in a lean atmosphere, thereby reducing and purifying NOx.

Assignees

• Toyota Motor Co Ltd

Inventors

• Nagao Satoshi
• Akashi Kazutoshi

Classifications

• B01J2235/00

  Indexing scheme associated with group B01J35/00, related to the analysis techniques used to determine the catalysts form or properties · CPC title

• B01J2235/10

  Infrared [IR] · CPC title

• B01J35/393

  Metal or metal oxide crystallite size · CPC title

• B01J2235/30

  Scanning electron microscopy; Transmission electron microscopy · CPC title

• B01J35/45

  Nanoparticles · CPC title