Synergized PGM close-coupled catalysts for TWC applications

• US 9,700,841 B2
• Filed: 03/13/2015
• Issued: 07/11/2017
• Est. Priority Date: 03/13/2015
• Status: Expired due to Fees

• Current Assignee: Clean Diesel Technologies, Inc.
• Original Assignee: BYD Company Limited
• Inventors: Golden, Stephen J.
• Primary Examiner(s): Duong, Tom P
• Application Number:
  US14/657,842
• Publication Number:
  US 20160263526A1
• Time in Patent Office: 851 Days
• Field of Search: 422170, 422177
• CPC Class Codes: B01D 2255/1023 Palladium
• CPC Class Codes: B01D 2255/1025 Rhodium
• CPC Class Codes: B01D 2255/2073 Manganese
• CPC Class Codes: B01D 2255/20761 Copper
• CPC Class Codes: B01D 2255/405 Spinels
• CPC Class Codes: B01D 2258/014 Stoichiometric gasoline engines
• 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 23/34 Manganese
• CPC Class Codes: B01J 23/464 Rhodium
• CPC Class Codes: B01J 23/72 Copper
• CPC Class Codes: B01J 23/8892 Manganese
• CPC Class Codes: B01J 23/8986 with manganese, technetium or rhenium
• CPC Class Codes: B01J 35/19 Catalysts containing parts with different compositions
• CPC Class Codes: F01N 13/009 having two or more separate purifying devices arranged in series
• CPC Class Codes: F01N 13/0097 the purifying devices are arranged in a single housing
• CPC Class Codes: F01N 3/101 Three-way catalysts
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

Synergized PGM catalyst converters configured as three-way catalyst (TWC) systems are disclosed. The disclosed SPGM system configurations exhibit high thermal stability, attenuated air to fuel (A/F) perturbations, enhanced TWC activity, and high catalytic conversion efficiency as a result of synergizing a low PGM loading close-coupled catalyst (CCC), with Ce-based oxygen storage, with a front spinel zone of suitable mixed metal oxide compositions acting as pre-catalyst for oxygen storage. The attenuation of A/F perturbations to lower amplitude, before exhaust gas emissions go into the standard PGM CCC, allows the system to work within a range of R values very close to the stoichiometric point for both lean and rich conditions, and high catalytic conversion efficiency in NO_X, CO, and HC conversions. The disclosed SPGM system configurations can be utilized in a plurality of TWC applications, such as conventional TWC systems including an optional underfloor catalyst.

Claims

1. A catalytic system, comprising:

a first catalytic apparatus comprising at least two catalytic portions; and

a second catalytic apparatus comprising at least one catalytic portion;

wherein one of the at least two catalytic portions of the first catalytic apparatus comprises at least one binary spinel composition and wherein one of the at least two catalytic portions of the first catalytic apparatus comprises a close-coupled catalyst; and

wherein the at least one catalytic portion of the second catalytic apparatus comprises a platinum group metal.

2. The catalytic system of claim 1, wherein the second catalytic apparatus forms a portion of an automotive underfloor catalyst.

3. The catalytic system of claim 1, wherein the at least one binary spinel composition is formed from metals selected from the group consisting of aluminum, magnesium, manganese, gallium, nickel, copper, silver, cobalt, iron, chromium, titanium, tin, and mixtures thereof.

4. The catalytic system of claim 1, wherein the at least one binary spinel composition comprises a Cu—

Mn spinel structure.

5. The catalytic system of claim 1, wherein at least one of the at least two catalytic portions of the first catalytic apparatus comprises a substrate having disposed thereto a catalyst at a thickness of between one and two inches.

6. The catalytic system of claim 1, wherein the conversion of CO in an applied lean exhaust stream is greater than 95%.

7. The catalytic system of claim 1, wherein the conversion of NO in an applied lean exhaust stream is greater than 98%.

8. The catalytic system of claim 1, wherein the conversion of hydrocarbons in an applied lean exhaust stream is greater than 96%.

9. The catalytic system of claim 1, wherein the close-coupled catalyst comprises Pd and Rh.

10. The catalytic system of claim 1, wherein the close-coupled catalyst comprises Pd and Rh;

wherein the Pd is present at about between 6 g/ft³ and 20 g/ft³, and the Rh is present at about 6 g/ft³.

11. The catalytic system of claim 1, wherein the close-coupled catalyst comprises about 60% by weight of Cu—

Mn spinel.

12. The catalytic system of claim 1, wherein the close-coupled catalyst comprises about 40% by weight of a platinum group metal.

13. The catalytic system of claim 1, wherein the close-coupled catalyst comprises at least a layer of PGM catalyst material overlying a Ce-based oxygen storage material substrate.