Exhaust gas purification catalyst

Patent metadata

Field	Value
Publication number	US-12138618-B2
Application number	US-202017638909-A
Country	US
Kind code	B2
Filing date	Jul 30, 2020
Priority date	Sep 2, 2019
Publication date	Nov 12, 2024
Grant date	Nov 12, 2024

Abstract

The present invention provides an exhaust gas purification catalyst including a base material 11 and a catalyst layer 20 provided on the base material 11 . The catalyst layer 20 includes: a catalyst metal; and a carrying material 21 carrying the catalyst metal. The carrying material 21 includes: an OSC material 22 having an oxygen storage capacity; and a carrier 23 other than the OSC material. The OSC material 22 has a mean particle diameter Dx of 1.5 μm or more which is larger than the mean particle diameter Dy of the carrier 23 other than the OSC material 22.

First claim

The invention claimed is:

1. An exhaust gas purification catalyst comprising:
a base material and
a catalyst layer provided on the base material,
the catalyst layer including: a catalyst metal and a carrying material carrying the catalyst metal,
the carrying material including: an OSC material having an oxygen storage capacity and a carrier other than the OSC material,
the OSC material having a mean particle diameter Dx in volume base based on electron microscopy of 1.5 μm or more which is larger than a mean particle diameter Dy in volume base based on electron microscopy of the carrier other than the OSC material and
wherein the mean particle diameter Dy is 0.7 μm or more and 2 μm or less.

2. The exhaust gas purification catalyst according to claim 1 , wherein a ratio (Dx/Dy) of the mean particle diameter Dx of the OSC material to the mean particle diameter Dy of the carrier other than the OSC material is 1.3 or more to 20 or less.

3. The exhaust gas purification catalyst according to claim 2 , wherein a content ratio of the carrier other than the OSC material relative to 100 parts by mass of the OSC material is 25 parts by mass to 200 parts by mass.

4. The exhaust gas purification catalyst according to claim 3 , wherein the OSC material has the mean particle diameter Dx of 15 μm or less.

5. The exhaust gas purification catalyst according to claim 3 , wherein the OSC material is a Ce-containing oxide including ceria.

6. The exhaust gas purification catalyst according to claim 2 , wherein the OSC material has the mean particle diameter Dx of 15 μm or less.

7. The exhaust gas purification catalyst according to claim 2 , wherein the OSC material is a Ce-containing oxide including ceria.

8. The exhaust gas purification catalyst according to claim 2 , wherein the carrier other than the OSC material is an Al-containing oxide including alumina.

9. The exhaust gas purification catalyst according to claim 2 , wherein the catalyst layer is formed on a surface of the base material, and a second catalyst layer including a catalyst metal is formed on the catalyst layer, the catalyst metal being different in kind from the catalyst metal of the catalyst layer.

10. The exhaust gas purification catalyst according to claim 1 , wherein a content ratio of the carrier other than the OSC material relative to 100 parts by mass of the OSC material is 25 parts by mass to 200 parts by mass.

11. The exhaust gas purification catalyst according to claim 1 , wherein the OSC material has the mean particle diameter Dx of 15 μm or less.

12. The exhaust gas purification catalyst according to claim 1 , wherein the OSC material is a Ce-containing oxide including ceria.

13. The exhaust gas purification catalyst according to claim 1 , wherein the carrier other than the OSC material is an Al-containing oxide including alumina.

14. The exhaust gas purification catalyst according to claim 1 , wherein the catalyst layer is formed on a surface of the base material and wherein a second catalyst layer including a catalyst metal is formed on the catalyst layer, the catalyst metal being different in kind from the catalyst metal of the catalyst layer.

15. The exhaust gas purification catalyst according to claim 14 , wherein the catalyst layer includes Pd as the catalyst metal and wherein the second catalyst layer includes Rh as the catalyst metal.

16. The exhaust gas purification catalyst according to claim 1 , wherein, in an exhaust gas flow direction from an inlet from which the exhaust gas flows in toward an outlet from which the exhaust gas flows out, the catalyst layer has different compositions on an upstream side and a downstream side.

17. The exhaust gas purification catalyst according to claim 16 , wherein when the catalyst layer is divided in the exhaust gas flow direction into an early-stage portion near the inlet and a later-stage portion near the outlet, the early-stage portion includes a higher amount of the carrier other than the OSC material than the later-stage portion.

Assignees

• Cataler Corp

Inventors

• Ota Takaya
• Oishi Shunsuke
• 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

• B01J2235/30

  Scanning electron microscopy; Transmission electron microscopy · CPC title

• B01J35/56

  Foraminous structures having flow-through passages or channels, e.g. grids or three-dimensional [3D] monoliths · CPC title

• B01J35/19

  Catalysts containing parts with different compositions · CPC title

• F01N2370/02

  used in catalytic reactors · CPC title