Exhaust gas purification catalyst

Patent metadata

Field	Value
Publication number	US-12275001-B2
Application number	US-202017801091-A
Country	US
Kind code	B2
Filing date	Dec 7, 2020
Priority date	Feb 21, 2020
Publication date	Apr 15, 2025
Grant date	Apr 15, 2025

Abstract

In accordance with the technology herein disclosed, an exhaust gas purification catalyst exhibiting a high exhaust gas purifying performance using a new rare earth-containing material is provided. The exhaust gas purification catalyst herein disclosed includes a base material and a catalyst layer formed on the surface of the base material. The catalyst layer of such an exhaust gas purification catalyst includes rare earth-carrying alumina 50 including a primary particle of a rare earth particle 40 including at least one rare earth element carried on the surface of an alumina carrier 30 including alumina, and the average particle diameter D 50 based on TEM observation of the rare earth particle 40 in the rare earth-carrying alumina 50 is 10 nm or less. As a result of this, it is possible to provide an exhaust gas purification catalyst having high NOx adsorption performance and CO adsorption performance.

First claim

The invention claimed is:

1. An exhaust gas purification catalyst arranged in an exhaust passage of an internal combustion engine for purifying an exhaust gas exhausted from the internal combustion engine,
the exhaust gas purification catalyst comprising:
a base material and
a catalyst layer formed on a surface of the base material,
wherein the catalyst layer includes rare-earth-carrying alumina having a primary particle of a rare-earth particle including at least one rare-earth element carried on a surface of an alumina carrier, and
an average particle diameter D50 based on TEM observation of the rare-earth particle in the rare-earth-carrying alumina is 10 nm or less.

2. The exhaust gas purification catalyst according to claim 1 , wherein the catalyst layer further includes a noble metal catalyst.

3. The exhaust gas purification catalyst according to claim 1 , wherein an oxide equivalent weight of the rare-earth particle is 5 wt % or more and 20 wt % or less when an oxide equivalent weight of the alumina carrier is assumed to be 100 wt %.

4. The exhaust gas purification catalyst according to claim 1 , wherein a specific surface area of the alumina carrier after carrying out a 1000° C. durability test for 10 hours is 50 m 2 /g or more.

5. The exhaust gas purification catalyst according to claim 1 , wherein the rare-earth particle includes at least one or more rare-earth elements selected from the group consisting of Y, La, Ce, Pr, and Nd.

6. The exhaust gas purification catalyst according to claim 5 , wherein the rare-earth particle includes Ce as a main element.

7. The exhaust gas purification catalyst according to claim 6 , wherein the rare-earth particle has an oxide equivalent weight of the elements other than Ce of 80 wt % or less based on a 100 wt % of the rare-earth element.

8. The exhaust gas purification catalyst according to claim 5 , wherein the catalyst layer includes La as the main element of the rare-earth particle and includes Pd as a noble metal catalyst.

Assignees

• Cataler Corp

Inventors

• Oishi Shunsuke
• Ota Takaya
• Miura Taku
• Togashi Hiromi
• Takasu Ryosuke

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

• B01J35/45

  Nanoparticles · CPC title

• B01J35/613

  10-100 m2/g · CPC title

• B01J21/04

  Alumina · CPC title

• B01D2258/01

  Engine exhaust gases · CPC title