ZPGM Underfloor Catalyst for Hybrid Exhaust Treatment Systems

• US 20150147239A1
• Filed: 11/26/2013
• Published: 05/28/2015
• 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., Launois, Maxime
• Application Number:
  US14/090,821
• Publication Number:
  US 20150147239A1
• Time in Patent Office: Days
• US Class Current: 422/180
• 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 2255/20761 Copper
• 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: Y02T 10/12 Improving ICE efficiencies

Abstract

Hybrid PGM-ZPGM exhaust treatment systems are disclosed. The systems include a PGM close-couple catalytic converter followed by an underfloor ZPGM catalytic converter. The disclosed hybrid systems, including PGM based catalysts and zero-PGM based catalysts may replace pure PGM based exhaust treatment systems. The ZPGM catalyst compositions used may include copper and cerium as active ZPGM catalysts. The disclosed ZPGM underfloor converters may be designed to convert leaks from close-couple converters.

Claims

1. A catalyst system for use during an urban drive cycle, the catalyst system comprising:

at least one close-couple converter; and

at least one underfloor converter;

wherein the underfloor converter comprises a zero platinum group metal (ZPGM) catalyst system, comprising;

a substrate;

a washcoat suitable for deposition on the substrate, comprising at least one first oxygen storage material and alumina; and

an overcoat suitable for deposition on the substrate, comprising at least one second oxygen storage material and one selected from the group comprising copper oxide, ceria, alumina, and mixtures thereof.

2. The catalyst system of claim 1, wherein the at least one first oxygen storage material comprises at least one selected from the group consisting of cerium, zirconium, and mixtures thereof.

3. The catalyst system of claim 1, wherein the ratio of the at least one first oxygen storage material to alumina in the washcoat is 60:

40.

4. The catalyst system of claim 1, wherein the at least one second oxygen storage material comprises at least one selected from the group consisting of cerium, zirconium, and mixtures thereof.

5. The catalyst system of claim 1, wherein the ratio of the at least one first oxygen storage material to alumina in the overcoat is 60:

40.

6. The catalyst system of claim 1, wherein the substrate is metallic.

7. The catalyst system of claim 1, wherein the first oxygen storage material comprises cerium, zirconium, lanthanum, yttrium, lanthanides, actinides, and mixtures thereof.

8. The catalyst system of claim 1, wherein the second oxygen storage material comprises cerium, zirconium, lanthanum, yttrium, lanthanides, actinides, and mixtures thereof.

9. The catalyst system of claim 1, wherein the conversion of HC is at substantially the same rate as for a catalyst system containing platinum group metals.

10. The catalyst system of claim 1, wherein the conversion of NoxC is at substantially the same rate as for a catalyst system containing platinum group metals.

11. The catalyst system of claim 1, wherein the conversion of HC is at substantially the same rate as for a catalyst system containing platinum group metals when under Extra Urban Driving Cycle conditions.

12. The catalyst system of claim 1, wherein the conversion of NOx is at substantially the same rate as for a catalyst system containing platinum group metals when under Extra Urban Driving Cycle conditions.

13. The catalyst system of claim 1, wherein the close-couple converter is proximate to an exhaust manifold.

14. The catalyst system of claim 1, wherein the at least one underfloor converter effectively converts at least a portion of unconverted exhaust from the at least one close-couple converter.