Sulfur Resistance of Zero-PGM for Diesel Oxidation Application

• US 20160121304A1
• Filed: 10/29/2014
• Published: 05/05/2016
• Est. Priority Date: 10/29/2014
• Status: Abandoned Application

• Current Assignee: Clean Diesel Technologies, Inc.
• Original Assignee: CDTI
• Inventors: Nazarpoor, Zahra, Golden, Stephen J.
• Application Number:
  US14/527,494
• Publication Number:
  US 20160121304A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B01D 2255/1023 Palladium
• CPC Class Codes: B01D 2255/2042 Barium
• CPC Class Codes: B01D 2255/2065 Cerium
• CPC Class Codes: B01D 2255/402 Perovskites
• CPC Class Codes: B01D 2255/405 Spinels
• CPC Class Codes: B01D 2258/012 Diesel engines and lean burn gasoline engines
• CPC Class Codes: B01D 53/944 Simultaneously removing carbon monoxide, hydrocarbons or carbon making use of oxidation catalysts three-way-catalysts [TWC] B01D53/9445
• CPC Class Codes: B01D 53/949 for storing sulfur oxides
• CPC Class Codes: B01J 23/002 Mixed oxides other than spinels, e.g. perovskite
• CPC Class Codes: B01J 23/005 Spinels
• CPC Class Codes: B01J 23/34 Manganese
• CPC Class Codes: B01J 23/63 with rare earths or actinides
• CPC Class Codes: B01J 23/6562 Manganese
• CPC Class Codes: B01J 23/8892 Manganese
• CPC Class Codes: B01J 23/8986 with manganese, technetium or rhenium
• CPC Class Codes: B01J 2523/00 Constitutive chemical elements of heterogeneous catalysts
• CPC Class Codes: B01J 2523/17 Copper
• CPC Class Codes: B01J 2523/25 Barium
• CPC Class Codes: B01J 2523/36 Yttrium
• CPC Class Codes: B01J 2523/3712 Cerium
• CPC Class Codes: B01J 2523/3718 : Praseodymium
• CPC Class Codes: B01J 2523/48 : Zirconium
• CPC Class Codes: B01J 2523/72 : Manganese
• CPC Class Codes: B01J 2523/824 : Palladium
• CPC Class Codes: B01J 35/19 : Catalysts containing parts with different compositions
• CPC Class Codes: B01J 37/0242 : Coating followed by impregnation
• CPC Class Codes: B01J 37/0248 : Coatings comprising impregnated particles

Abstract

Sulfur tolerant oxidation catalysts with significant oxidation capabilities are disclosed. A plurality of catalyst samples may be prepared including ZPGM material compositions of YMnO₃ perovskite, Cu_xMn_3-xO₄ spinel, and a combination of both, supported on doped Zirconia and cordierite substrate, and front zoned with sulfur getters of Pd, Ba acetate, and Ce nitrate. Testing of samples may be performed under standard and sulfated DOC conditions to assess influence of adding front zoned sulfur getters to ZPGM catalyst samples. Levels of NO oxidation and HC conversion may be compared, and resistance to sulfur and catalytic stability may be observed to determine ZPGM samples zoned with sulfur getter which may provide the most significant improvements in NO oxidation, HC conversion, CO selectivity, and resistance to sulfur for use in DOC applications.

Claims

1. A catalyst, comprising:

at least one zero platinum group metal (ZPGM) in combination with Pd, wherein the catalyst provides substantially constant NO conversion levels before and after sulfation.

2. The catalyst of claim 1, wherein the Pd is present in the front zone of a catalyst system.

3. The catalyst of claim 2, wherein a washcoat of the catalyst system comprises the front zone.

4. The catalyst of claim 1, wherein the catalyst is heated to about 340°

C.

5. The catalyst of claim 1, wherein the ZPGM comprises one selected from the group comprising a perovskite structure, a spinel structure, or a mixed phase of perovskite and spinel.

6. The catalyst of claim 1, wherein the ZPGM catalyst comprises at least one perovskite structure having a general formula of YMnO₃.

7. The catalyst of claim 1, wherein the catalyst provides resistance to sulfur before and after sulfation.

8. The catalyst of claim 1, wherein NO conversion is greater than 60%.

9. A catalytic system, comprising:

a substrate;

an overcoat suitable for deposition on the substrate, comprising at least one first zero platinum group metal (ZPGM) catalyst; and

at least one washcoat suitable for deposition on the substrate, comprising at least one second ZPGM catalyst in combination with Pd;

wherein the at least one second ZPGM catalyst in combination with Pd is present in a front zone of the at least one washcoat and provides substantially constant NO conversion levels before and after sulfation.

10. The catalytic system of claim 9, wherein the washcoat comprises at least layer of at least one third ZPGM catalyst in a zone behind the front zone.

11. The catalyst system of claim 10, wherein the at least one third ZPGM catalyst comprises at least one perovskite structure having a general formula of YMnO₃.

12. The catalyst system of claim 9, wherein the front zone further comprises at least one selected from the group comprising an OSM, Ba, Ce, and combination thereof.

13. The catalyst system of claim 9, wherein the catalyst is heated to about 340°

C.

14. The catalyst system of claim 9, wherein the catalyst provides resistance to sulfur before and after sulfation.

15. The catalyst system of claim 9, wherein NO conversion is greater than 60%.

16. The catalyst system of claim 9, wherein HC conversion is greater than 60%.