APPLICATION OF SYNERGIZED-PGM WITH ULTRA-LOW PGM LOADINGS AS CLOSE-COUPLED THREE-WAY CATALYSTS FOR INTERNAL COMBUSTION ENGINES

• US 20170328250A1
• Filed: 05/04/2017
• Published: 11/16/2017
• Est. Priority Date: 05/12/2016
• Status: Active Grant

• Current Assignee: Clean Diesel Technologies, Inc.
• Original Assignee: Clean Diesel Technologies, Inc.
• Inventors: Nazarpoor, Zahra, Golden, Stephen J., Launois, Maxime
• Granted Patent: US 10,533,472 B2
• Time in Patent Office: Days
• CPC Class Codes: B01D 2255/102 Platinum group metals
• CPC Class Codes: B01D 2255/1021 Platinum
• CPC Class Codes: B01D 2255/1023 Palladium
• CPC Class Codes: B01D 2255/1025 Rhodium
• CPC Class Codes: B01D 2255/1026 Ruthenium
• CPC Class Codes: B01D 2255/1028 Iridium
• CPC Class Codes: B01D 2255/2022 Potassium
• CPC Class Codes: B01D 2255/2027 Sodium
• CPC Class Codes: B01D 2255/2042 Barium
• CPC Class Codes: B01D 2255/2045 Calcium
• CPC Class Codes: B01D 2255/2047 Magnesium
• CPC Class Codes: B01D 2255/2063 Lanthanum
• 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 2255/20707 Titanium
• CPC Class Codes: B01D 2255/2073 Manganese
• CPC Class Codes: B01D 2255/20738 Iron
• CPC Class Codes: B01D 2255/20746 Cobalt
• CPC Class Codes: B01D 2255/20753 Nickel
• CPC Class Codes: B01D 2255/20761 : Copper
• CPC Class Codes: B01D 2255/20784 : Chromium
• CPC Class Codes: B01D 2255/20792 : Zinc
• CPC Class Codes: B01D 2255/2092 : Aluminium
• CPC Class Codes: B01D 2255/405 : Spinels
• CPC Class Codes: B01D 2255/65 : Catalysts not containing noble metals
• CPC Class Codes: B01D 2255/9022 : Two layers
• CPC Class Codes: B01D 2255/9025 : Three layers
• CPC Class Codes: B01D 2255/904 : Multiple catalysts
• CPC Class Codes: B01D 2257/404 : Nitrogen oxides other than dinitrogen oxide
• CPC Class Codes: B01D 2257/502 : Carbon monoxide
• CPC Class Codes: B01D 2257/702 : Hydrocarbons
• CPC Class Codes: B01D 2258/01 : Engine exhaust gases
• CPC Class Codes: B01D 53/945 : characterised by a specific catalyst
• CPC Class Codes: B01D 53/9468 : in different layers
• 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 23/42 : Platinum
• CPC Class Codes: B01J 23/464 : Rhodium
• CPC Class Codes: B01J 23/755 : Nickel
• CPC Class Codes: F01N 13/0093 : the purifying devices are of the same type
• CPC Class Codes: F01N 2370/02 : used in catalytic reactors
• CPC Class Codes: F01N 2510/06 : for exhaust purification, e.g. catalytic reaction
• CPC Class Codes: F01N 3/0864 : Oxygen
• CPC Class Codes: F01N 3/101 : Three-way catalysts
• CPC Class Codes: Y02T 10/12 : Improving ICE efficiencies

Abstract

Synergized platinum group metals (SPGM) with ultra-low PGM loadings employed as close-coupled (CC) three-way catalysts (TWC) systems with varied material compositions and configurations are disclosed. SPGM CC catalysts in which ZPGM compositions of binary or ternary spinel structures supported onto support oxides are coupled with commercialized PGM UF catalysts and tested under Federal Test Procedure FTP-75 within TGDI and PI engines. The performance of the TWC systems including SPGM CC (with ultra-low PGM loadings) catalyst and commercialized PGM UF catalyst is compared to the performance of commercialized PGM CC and PGM UF catalysts. The disclosed TWC systems indicate that SPGM CC TWC catalytic performance is comparable or even exceeds high PGM-based conventional TWC catalysts, with reduced tailpipe emissions.

Claims

1. A catalytic system for treating an exhaust stream of a combustion engine, comprising

a combustion engine;

a close-coupled catalytic converter configured to accept at least one exhaust gas stream from said combustion engine, the close-coupled catalytic converter comprising a synergized platinum group metal catalyst comprising a zero platinum group metal spinel catalyst composition and an ultra-low platinum group metal catalyst material, wherein the platinum group metal catalyst material has a platinum group metal concentration of about 1 g/ft³ to about 10 g/ft³; and

an underfloor catalytic converter downstream of, and, in fluid communication with said close-coupled catalytic converter, the underfloor catalytic converter comprising a platinum group metal catalyst.

2. The catalytic system of claim 1, wherein the underfloor catalytic converter has a platinum group metal concentration of about 10 to 100 g/ft³.

3. The catalytic system of claim 1, wherein the platinum group metal of the underfloor catalytic converter is selected from the group consisting of platinum, palladium, ruthenium, iridium, and rhodium.

4. The catalytic system of claim 3, wherein the platinum group metal of the underfloor catalytic converter comprises a combination of platinum and rhodium.

5. The catalytic system of claim 1, wherein the spinel catalyst composition comprises a binary spinel having the general formula A_xB_3-xO₄ wherein X is from 0.01 to 2.99, and A and B are selected from the group consisting of sodium, potassium, calcium, barium, zinc, cadmium, aluminum, magnesium, manganese, nickel, copper, cobalt, iron, chromium, titanium, cerium, strontium, lanthanum, praseodymium, neodymium, samarium, indium, and mixtures thereof.

6. The catalytic system of claim 5, wherein the binary spinel comprises a Ni—

Fe spinel.

7. The catalytic system of claim 6, wherein the Ni—

Fe spinel comprises Ni_0.5Fe_2.5O₄.

8. The catalytic system of claim 1, wherein the spinel catalyst composition comprises at least one substrate, and a catalyst composition comprising a spinel oxide having the formula A_XB_YM_3-X-Y where X is from about 0.01 to about 1.99 and Y is from about 0.01 to about 1.0, and wherein A, B, and M are different from each other, and are selected from the group consisting of sodium, potassium, calcium, barium, zinc, cadmium, aluminum, magnesium, manganese, nickel, copper, cobalt, iron, chromium, titanium, cerium, strontium, lanthanum, praseodymium, neodymium, samarium, indium, and mixtures thereof.

9. The catalytic system of claim 1, wherein the spinel catalyst composition is supported onto a support oxide selected from the group consisting of Al₂O₃, doped Al₂O₃, ZrO₂, doped ZrO₂, SiO₂, doped SiO₂, TiO₂, doped TiO₂, doped Al₂O₃—

ZrO₂, Nb₂O₅, and mixtures thereof.

10. The catalytic system of claim 1, wherein the spinel catalyst composition is deposited onto a substrate as a washcoat layer, and the ultra-low platinum group metal catalyst material is deposited onto said washcoat layer as an overcoat layer.

11. The catalytic system of claim 1, wherein the platinum group metal of the ultra-low platinum group metal catalyst is selected from the group consisting of platinum, palladium, ruthenium, iridium, and rhodium.

12. The catalytic system of claim 1, wherein the platinum group metal of the ultra-low platinum group metal catalyst comprises a combination of platinum and rhodium.

13. The catalytic system of claim 1, wherein the amount of platinum in the ultra-low platinum group metal catalyst material is from about 1 to 5 g/ft³, and the amount of rhodium in the ultra-low platinum group metal catalyst material is from about 1 to 5 g/ft³.

14. The catalytic system of claim 13, wherein the platinum and rhodium of the ultra-low platinum group metal catalyst material are present in a 1:

1 ratio.

15. The catalytic system of claim 1, wherein the spinel catalyst composition comprises a Ni—

Fe binary spinel structure supported onto a doped Al₂O₃—

ZrO₂ support oxide.

16. The catalytic system of claim 1, wherein the underfloor catalytic converter comprises a combination of platinum and rhodium, and wherein the total amount of platinum group metals in said underfloor catalytic converter is from about 15 to 25 g/ft³.

17. The catalytic system of claim 1, wherein the platinum group metal catalyst of the synergized platinum group metal catalyst is free of rare earth metals and oxygen storage materials.

18. The catalytic system of claim 1, wherein the catalytic system exhibits a reduction in tailpipe emissions of NOx, CO, and THC in comparison to a similar system having a platinum group metal catalyst as the close-coupled catalytic converter in lieu of said synergized platinum group metal catalyst.

19. A method for removing pollutants from an exhaust stream of a combustion engine, comprising

introducing an exhaust stream of the combustion engine into a close-coupled catalytic converter comprising a synergized platinum group metal catalyst comprising a zero platinum group metal spinel catalyst composition and an ultra-low platinum group metal catalyst material, wherein the platinum group metal catalyst has a concentration of about 1 g/ft³ to about 10 g/ft³ to thereby at least partially catalytically convert NOx, CO, and THC;

introducing the at least partially catalytically converted exhaust stream into an underfloor catalytic converter comprising a platinum group metal catalyst.

20. The method of claim 19, wherein the spinel catalyst composition comprises a Ni—

Fe binary spinel structure supported onto a doped Al₂O₃—

ZrO₂ support oxide.