Catalyst element

• US 7,045,483 B2
• Filed: 01/18/2002
• Issued: 05/16/2006
• Est. Priority Date: 01/19/2001
• Status: Active Grant

• Current Assignee: NGK Insulators Limited
• Original Assignee: NGK Insulators Limited
• Inventors: Suzuki, Junichi, Noda, Naomi, Yamada, Kanji
• Primary Examiner(s): BOS, STEVEN J
• Application Number:
  US10/257,211
• Publication Number:
  US 20030083197A1
• Time in Patent Office: 1,579 Days
• Field of Search: 502/243, 502/250, 502/340, 502/344, 423/212, 423/349.1, 423/239.1
• US Class Current: 502/243
• CPC Class Codes: B01D 2255/1021 Platinum
• CPC Class Codes: B01D 2255/2022 Potassium
• CPC Class Codes: B01D 2255/2042 Barium
• CPC Class Codes: B01D 2255/2047 Magnesium
• CPC Class Codes: B01D 2255/91 NOx-storage component incorporated in the catalyst
• CPC Class Codes: B01D 53/9422 for removing nitrogen oxides by NOx storage or reduction by cyclic switching between lean and rich exhaust gases (LNT, NSC, NSR)
• CPC Class Codes: B01D 53/945 characterised by a specific catalyst
• CPC Class Codes: B01J 23/02 of the alkali- or alkaline earth metals or beryllium
• CPC Class Codes: B01J 23/58 with alkali- or alkaline earth metals
• CPC Class Codes: B01J 37/0244 Coatings comprising several layers
• CPC Class Codes: B01J 37/0248 Coatings comprising impregnated particles
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

A catalyst body is obtained by loading, on a carrier, a catalyst layer containing an alkali metal and/or an alkaline earth metal, wherein at least one kind of alkali metal and/or alkaline earth metal is allowed to be present in the carrier and/or between the carrier and the catalyst layer. With this catalyst body, the deterioration of the carrier caused by the alkali metal, etc. is prevented effectively and the long-term use has been made possible.

Claims

1. A catalyst body comprising:

a carrier, and

a catalyst layer containing a catalyst layer alkali metal and/or alkaline earth metal loaded on the carrier,

wherein the carrier is impregnated with a carrier alkali metal and/or alkaline earth metal prior to loading of the catalyst layer.

2. A catalyst body according to claim 1, wherein the carrier is impregnated with the carrier alkali metal and/or alkaline earth metal by infiltrating the carrier alkali metal and/or alkaline earth metal into the carrier.

3. A catalyst body according to claim 1, wherein the carrier is a honeycomb carrier.

4. A catalyst body according to claim 2, wherein the carrier is a honeycomb carrier.

5. A catalyst body according to claim 3, wherein the honeycomb carrier carries 0.05 to 3.0 mole/L of the carrier alkali metal and/or alkaline earth metal per unit volume of the honeycomb carrier.

6. A catalyst body according to claim 4, wherein the honeycomb carrier carries 0.05 to 3.0 mole/L of the carrier alkali metal and/or alkaline earth metal per unit volume of the honeycomb carrier.

7. A catalyst body according to claim 2, wherein the concentration of the carrier alkali metal and/or alkaline earth metal in the carrier is higher than the concentration of the catalyst layer alkali metal and/or alkaline earth metal in the catalyst layer.

8. A catalyst body according to claim 1, wherein the main constituent material of the carrier is cordierite.

9. A catalyst body according to claim 1, wherein the carrier alkali metal and/or alkaline earth metal is also present between the carrier and the catalyst layer.

10. A catalyst body comprising:

a carrier,

a catalyst layer containing a catalyst layer alkali metal and/or alkaline earth metal, and

an intermediate layer containing an intermediate layer alkali metal and/or alkaline earth metal,

wherein said intermediate layer is formed by at least partially coating said carrier with said intermediate layer alkali metal and/or alkaline earth metal, and said catalyst layer is formed on said intermediate layer by loading a catalyst containing said catalyst layer alkali metal and/or alkaline earth metal, and

wherein the concentration of the intermediate layer alkali metal and/or alkaline earth metal contained in said intermediate layer is higher than the concentration of the catalyst layer alkali metal and/or alkaline earth metal contained in said catalyst layer.

11. A catalyst body according to claim 10, wherein the intermediate layer has a thickness of 0.5 times or less the thickness of the catalyst layer.

12. A catalyst body according to claim 10, wherein the intermediate layer has a thickness of 50 μ

m or less.

13. A catalyst body according to claim 10, wherein the carrier is a honeycomb carrier.

14. A catalyst body according to claim 13, wherein the honeycomb carrier carries 0.05 to 3.0 mole/L of the intermediate layer alkali metal and/or alkaline earth metal per unit volume of the honeycomb carrier.

15. A catalyst body according to claim 10, wherein the main constituent material of the carrier is cordierite.