Catalyst element

• US 20030083197A1
• Filed: 10/10/2002
• Published: 05/01/2003
• 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
• Granted Patent: US 7,045,483 B2
• Time in Patent Office: Days
• US Class Current: 502/344
• 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 an alkali metal and/or an alkaline earth metal, loaded on the carrier, characterized in that 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.

2. A catalyst body according to claim 1, wherein the 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 by, prior to the loading of the catalyst layer on the carrier, infiltrating the at least one kind of alkali metal and/or alkaline earth metal into the carrier and/or forming, on the carrier by coating, an intermediate layer containing the at least one kind of alkali metal and/or alkaline earth metal.

3. A catalyst body according to claim 1 or 2, wherein the carrier is a honeycomb carrier.

4. A catalyst body according to claim 3, wherein the amount of the at least one kind of alkali metal and/or alkaline earth metal loaded on the honeycomb carrier is 0.05 to 3.0 mole/L in terms of alkali metal element and/or alkaline earth metal element per unit volume of honeycomb carrier.

5. A catalyst body according to claim 2, wherein the intermediate layer has a thickness of 0.5 time or less the thickness of the catalyst layer.

6. A catalyst body according to claim 2, wherein the intermediate layer has a thickness of 50 μ

m or less.

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