Hybrid PGM-ZPGM TWC Exhaust Treatment Systems

• US 20150258496A1
• Filed: 05/28/2015
• Published: 09/17/2015
• Est. Priority Date: 11/26/2013
• Status: Abandoned Application

• Current Assignee: Clean Diesel Technologies, Inc.
• Original Assignee: Clean Diesel Technologies, Inc.
• Inventors: Hatfield, Randal L., Golden, Stephen J.
• Application Number:
  US14/723,688
• Publication Number:
  US 20150258496A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B01D 2255/1023 Palladium
• CPC Class Codes: B01D 2255/1025 Rhodium
• CPC Class Codes: B01D 2255/2065 Cerium
• CPC Class Codes: B01D 2255/2066 Praseodymium
• CPC Class Codes: B01D 2255/2068 Neodymium
• CPC Class Codes: B01D 2255/20715 Zirconium
• CPC Class Codes: B01D 2255/2073 Manganese
• CPC Class Codes: B01D 2255/20761 Copper
• CPC Class Codes: B01D 2255/2092 Aluminium
• CPC Class Codes: B01D 2255/405 Spinels
• CPC Class Codes: B01D 2255/9022 Two layers
• CPC Class Codes: B01D 2255/908 O2-storage component incorporated in the catalyst
• CPC Class Codes: B01D 53/945 characterised by a specific catalyst
• CPC Class Codes: B01D 53/9477 with catalysts positioned on separate bricks, e.g. exhaust systems
• CPC Class Codes: B01J 23/005 Spinels
• CPC Class Codes: B01J 23/40 of the platinum group metals
• 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 2523/3718 : Praseodymium
• CPC Class Codes: B01J 2523/48 : Zirconium
• CPC Class Codes: B01J 2523/56 : Niobium
• CPC Class Codes: B01J 2523/72 : Manganese
• CPC Class Codes: B01J 35/19 : Catalysts containing parts with different compositions
• CPC Class Codes: B01J 37/0244 : Coatings comprising several layers
• CPC Class Codes: Y02T 10/12 : Improving ICE efficiencies

Abstract

Hybrid PGM-ZPGM three-way catalyst (TWC) exhaust treatment systems are disclosed. The hybrid PGM-ZPGM TWC systems include a PGM close-coupled catalytic converter followed by an underfloor catalytic converter. The underfloor catalytic converter includes a ZPGM-based catalyst. Additionally, the underfloor catalytic converter can also be a PGM/ZPGM zone coated catalytic converter. The disclosed hybrid TWC systems comprising PGM-based and ZPGM-based catalysts can replace pure PGM-based exhaust treatment systems.

Claims

1. A system for treating the exhaust of a combustion engine, comprising:

at least one exhaust manifold suitable for accepting at least one stream of exhaust;

a closed-couple converter having a first catalyst body comprising at least one platinum group metal catalyst; and

an underfloor converter having a second catalyst body consisting of a zero platinum group metal;

wherein the at least one exhaust manifold is communicatively coupled to the closed-couple converter and underfloor converter.

2. The system of claim 1, wherein the at least one platinum group metal catalyst is selected from the group consisting of platinum (Pt), palladium (Pd), ruthenium (Ru), iridium (Ir), rhodium (Rd), and combinations thereof.

3. The system of claim 1, wherein the second catalyst body includes at least one platinum group metal.

4. The system of claim 1, wherein the first catalyst body comprises a substrate, a washcoat layer, and an overcoat layer.

5. The system of claim 1, wherein the at least one platinum group metal catalyst is supported on a support oxide.

6. The system of claim 5, wherein the support oxide is selected from the group consisting of MgAl₂O₄, Al₂O₃—

BaO, Al₂O₃—

La₂O₃, ZrO₂—

CeO₂—

Nd₂O₃—

Y₂O₃, CeO₂—

ZrO₂, CeO₂, SiO₂, Alumina silicate, ZrO₂—

Y₂O₃—

SiO₂, Al₂O₃—

CeO₂, Al₂O₃—

SrO, TiO₂-10% ZrO₂, TiO₂-10% Nb₂O₅, SnO₂—

TiO₂, ZrO₂—

SnO₂—

TiO₂, BaZrO₃, BaTiO₃, BaCeO₃, ZrO₂—

P₆O₁₁, ZrO₂—

Y₂O₃, ZrO₂—

Nb₂O₅, Al—

Zr—

Nb, and Al—

Zr—

La, and combinations thereof,

7. The system of claim 1, wherein the zero platinum group metal catalyst is supported on a support oxide.

8. The system of claim 7, wherein the support oxide is selected from the group consisting of MgAl₂O₄, Al₂O₃—

BaO, Al₂O₃—

La₂O₃, ZrO₂—

CeO₂—

Nd₂O₃—

Y₂O₃, CeO₂—

ZrO₂, CeO₂, SiO₂, Alumina silicate, ZrO₂—

Y₂O₃—

SiO₂, Al₂O₃—

CeO₂, Al₂O₃—

SrO, TiO₂-10% ZrO₂, TiO₂-10% Nb₂O₅, SnO₂—

TiO₂, ZrO₂—

SnO₂—

TiO₂, BaZrO₃, BaTiO₃, BaCeO₃, ZrO₂—

P₆O₁₁, ZrO₂—

Y₂O₃, ZrO₂—

Nb₂O₅, Al—

Zr—

Nb, and Al—

Zr—

La, and combinations thereof,

9. The system of claim 1, wherein the zero platinum group metal catalyst comprises a spinel structure.

10. The system of claim 1, wherein the platinum group metal catalyst comprises a spinel structure.

11. The system of claim 1, wherein the second catalyst body comprises a substrate, a washcoat layer, and an overcoat layer.

12. The system of claim 11, wherein the washcoat layer comprises a carrier material oxide selected from the group consisting of alumina, silica, titanium dioxide, zirconium oxide, cerium oxide, and mixtures thereof.

13. The system of claim 1, wherein the first catalyst body and second catalyst body provide a conversion of NO_X at greater than 80% at 350°

C.

14. The system of claim 1, wherein the first catalyst body and second catalyst body provide a conversion of NO_X at greater than 95% at 500°

C.

15. The system of claim 1, wherein the first catalyst body and second catalyst body provide a conversion of THC at greater than 80% at 400°

C.

16. The system of claim 1, wherein the first catalyst body and second catalyst body provide a conversion of THC at greater than 90% at 400°

C.

17. The system of claim 1, wherein the first catalyst body and second catalyst body provide a conversion of CO at greater than 60% at 350°

C.

18. The system of claim 1, wherein the first catalyst body and second catalyst body provide a conversion of CO at greater than 70% at 500°

C.

19. A method for optimizing a catalytic system, comprising:

providing a catalyst system into at least one stream of combustion exhaust, comprising;

a first catalyst body comprising at least one platinum group metal catalyst; and

a second catalyst body consisting of a zero platinum group metal;

wherein at least one of the first and second catalyst body is suitable for converting at least one of NO, CO and HC through oxidation or reduction.

20. The system of claim 19, wherein the at least one platinum group metal catalyst is selected from the group consisting of platinum (Pt), palladium (Pd), ruthenium (Ru), iridium (Ir), rhodium (Rd), and combinations thereof.

21. The system of claim 19, wherein the second catalyst body includes at least one platinum group metal.

22. The system of claim 19, wherein the first catalyst body comprises a substrate, a washcoat layer, and an overcoat layer.

23. The system of claim 19, wherein the at least one platinum group metal catalyst is supported on a support oxide.