Sulfur-Resistant Synergized PGM Catalysts for Diesel Oxidation Application

• US 20160136618A1
• Filed: 11/19/2014
• Published: 05/19/2016
• Est. Priority Date: 11/19/2014
• Status: Abandoned Application

• Current Assignee: Clean Diesel Technologies, Inc.
• Original Assignee: Clean Diesel Technologies, Inc.
• Inventors: Nazarpoor, Zahra, Golden, Stephen J.
• Application Number:
  US14/548,035
• Publication Number:
  US 20160136618A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B01D 2255/1021 Platinum
• CPC Class Codes: B01D 2255/1023 Palladium
• CPC Class Codes: B01D 2255/2061 Yttrium
• CPC Class Codes: B01D 2255/2073 Manganese
• CPC Class Codes: B01D 2255/402 Perovskites
• CPC Class Codes: B01D 2255/9032 Two zones
• CPC Class Codes: B01D 2255/908 O2-storage component incorporated in the catalyst
• 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: B01J 23/40 of the platinum group metals
• CPC Class Codes: B01J 23/42 Platinum
• CPC Class Codes: B01J 23/44 Palladium
• CPC Class Codes: B01J 35/19 Catalysts containing parts with different compositions

Abstract

Sulfur-resistant SPGM catalysts with significant oxidation capabilities are disclosed. A plurality of catalyst samples may be prepared including ZPGM material compositions of YMnO₃ perovskite supported on doped Zirconia and cordierite substrate, and front zoned with Pd and Pt/Pd compositions. Incipient wetness and metallizing techniques may be used for the catalytic layers. Testing of samples may be performed under standard and sulfated DOC conditions to assess influence of adding PGM to ZPGM catalyst samples. Levels of NO oxidation and HC oxidation may be compared. Resistance to sulfur and catalytic stability may be observed under long-term sulfated DOC condition to determine SPGM catalyst samples for DOC applications which may provide the most significant improvements in NO oxidation, HC conversion, CO selectivity, and long-term resistance to sulfur.

Claims

1. A synergized platinum group metal (SPGM) catalyst system comprising:

a) a first catalyst comprising a platinum group metal (PGM) washcoat layer and a first substrate; and

b) a second catalyst comprising a zero platinum group metal (ZPGM) washcoat layer and a second substrate;

wherein the PGM catalyst is upstream of the ZPGM catalyst.

2. The SPGM catalyst of claim 1, wherein the ZPGM washcoat layer further comprises a doped support oxide.

3. The SPGM catalyst of claim 2, wherein the support oxide is a doped ZrO₂ support oxide.

4. The SPGM catalyst of claim 2, wherein the ZPGM washcoat layer further comprises base metal loadings.

5. The SPGM catalyst of claim 1, wherein the SPGM is a YMnO₃ perovskite.

6. The SPGM catalyst of claim 1, wherein the first substrate is a cordierite substrate.

7. The SPGM catalyst of claim 1, wherein the PGM washcoat layer comprises palladium, platinum, or both palladium and platinum.

8. The SPGM catalyst of claim 1, wherein the PGM washcoat layer further comprises an oxygen storage material (OSM).

9. The SPGM catalyst of claim 2, wherein the OSM comprises zirconia, lanthanides, alkaline earth metals, transition metals, or mixtures thereof.

10. The SPGM catalyst of claim 1, wherein the PGM washcoat layer further comprises Al₂O₃.

11. The SPGM catalyst of claim 1, wherein the PGM zone to ZPGM zone ratio is a 1:

2 ratio in diameter.

12. The SPGM catalyst of claim 2, wherein the support oxide is a Pr₆O₁₁—

ZrO₂ support oxide.

13. The SPGM catalyst of claim 9, wherein the OSM comprises barium or cerium.

14. The SPGM catalyst of claim 1, wherein the second substrate is a cordierite substrate.

15. A diesel oxidation catalyst (DOC) system comprising the synergized platinum group metal catalyst system according to claim 1.

30. A method of reducing sulfur poisoning comprising applying an exhaust gas stream to the diesel oxidation catalyst (DOC) system according to claim 15.

31. The SPGM catalyst of claim 1, wherein the SPGM catalyst converts about 90% of hydrocarbons.

32. The SPGM catalyst of claim 31, wherein the about 90% conversion of hydrocarbons remains constant over time.

16. A method of reducing sulfur poisoning comprising applying an exhaust gas stream to a synergized platinum group metal (SPGM) catalyst system comprising:

a) a first catalyst comprising a platinum group metal (PGM) washcoat layer and a first substrate; and

b) a second catalyst comprising a zero platinum group metal (ZPGM) washcoat layer and a second substrate;

wherein the PGM catalyst is upstream of the ZPGM catalyst.

17. The method of claim 16, wherein the ZPGM washcoat layer further comprises a doped support oxide.

18. The method of claim 17, wherein the support oxide is a doped ZrO₂ support oxide.

19. The method of claim 17, wherein the ZPGM washcoat layer further comprises base metal loadings.

20. The method of claim 16, wherein the SPGM is a YMnO₃ perovskite.

21. The method of claim 16, wherein the first substrate is a cordierite substrate.

22. The method of claim 16, wherein the PGM washcoat layer comprises palladium, platinum, or both palladium and platinum.

23. The method of claim 16, wherein the PGM washcoat layer further comprises an oxygen storage material (OSM).

24. The method of claim 17, wherein the OSM comprises zirconia, lanthanides, alkaline earth metals, transition metals, or mixtures thereof.

25. The method of claim 16, wherein the PGM washcoat layer further comprises Al₂O₃.

26. The method of claim 16, wherein the PGM zone to ZPGM zone ratio is a 1:

2 ratio in diameter.

27. The method of claim 17, wherein the support oxide is a Pr₆O₁₁—

ZrO₂ support oxide.

28. The method of claim 24, wherein the OSM comprises barium or cerium.

29. The method of claim 16, wherein the second substrate is a cordierite substrate.

33. The method of claim 16, wherein the SPGM catalyst converts about 90% of hydrocarbons.

34. The SPGM catalyst of claim 33, wherein the about 90% conversion of hydrocarbons remains constant over time.