Base Metal Activated Rhodium Coatings for Catalysts in Three-Way Catalyst (TWC) Applications

• US 20150352533A1
• Filed: 06/05/2015
• Published: 12/10/2015
• Est. Priority Date: 06/06/2014
• Status: Active Grant

• Current Assignee: Clean Diesel Technologies, Inc.
• Original Assignee: Clean Diesel Technologies, Inc.
• Inventors: Hatfield, Randal L., Golden, Stephen J., Ngo, Johnny T.
• Granted Patent: US 9,579,604 B2
• 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 2255/2042 Barium
• CPC Class Codes: B01D 2255/2061 Yttrium
• 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 2255/207 Transition metals
• CPC Class Codes: B01D 2255/20715 Zirconium
• CPC Class Codes: B01D 2255/20738 Iron
• CPC Class Codes: B01D 2255/209 Other metals
• CPC Class Codes: B01D 2255/2092 Aluminium
• CPC Class Codes: B01D 2255/40 Mixed oxides
• CPC Class Codes: B01D 2255/902 Multilayered catalyst
• 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 53/9454 characterised by a specific device
• CPC Class Codes: B01D 53/9472 in different zones
• CPC Class Codes: B01J 21/04 Alumina
• CPC Class Codes: B01J 23/002 : Mixed oxides other than spinels, e.g. perovskite
• CPC Class Codes: B01J 23/10 : of rare earths
• CPC Class Codes: B01J 23/20 : Vanadium, niobium or tantalum
• CPC Class Codes: B01J 23/63 : with rare earths or actinides
• CPC Class Codes: B01J 23/83 : with rare earths or actinides
• CPC Class Codes: B01J 23/8906 : Iron and noble metals
• CPC Class Codes: B01J 23/894 : with rare earths or actinides
• CPC Class Codes: B01J 2523/00 : Constitutive chemical elements of heterogeneous catalysts
• CPC Class Codes: B01J 27/232 : Carbonates
• CPC Class Codes: B01J 35/19 : Catalysts containing parts with different compositions
• CPC Class Codes: B01J 35/56 : Foraminous structures having flow-through passages or channels, e.g. grids or three-dimensional monoliths
• CPC Class Codes: B01J 37/0244 : Coatings comprising several layers
• CPC Class Codes: Y02A 50/20 : Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
• CPC Class Codes: Y02T 10/12 : Improving ICE efficiencies

Abstract

Close-coupled catalysts (CCC) for TWC applications are disclosed. The novel CCCs are implemented using light-weighted ceramic substrates in which a thin coating employing a low loading of Iron (Fe)-activated Rhodium (Rh) material composition, with Iron loadings and an OSM of Ceria-Zirconia, are deposited onto the substrates. Different CCC samples are produced to determine and/or verify improved light-off (LO) and NO_X conversion of the CCCs. Other CCC samples produced are a CCC including a standard (non-activated) Rh thin coating and a heavily loaded CCC with a single coating of Pd/Rh material composition. The CCC samples are aged under dyno-aging using the multi-mode aging cycle and their performance tested using a car engine with ports on the exhaust to measure the emissions, according to the testing protocol in the Environmental Protection Agency Federal Test Procedure 75. During testing, the thin coatings of Fe-activated Rh exhibit improved light-off and NO_x conversion efficiency.

Claims

1. A catalytic system comprising:

a ceramic substrate coated with Fe-activated Rh at a loading of about 90 g/L.

2. The catalytic system of claim 1, wherein the Fe-activated Rh is supported on a OSM comprising one selected from the group consisting of Ce, Zr, Nd, Pr, Y, and combinations thereof.

3. The catalyst system of claim 1, wherein the Fe is present at about 7% (w/w).

4. The catalyst system of claim 1, wherein the Rh is present at less than about 0.5% (w/w).

5. A catalytic system comprising:

a ceramic substrate coated with Fe-activated Rh;

wherein the Rh loadings are from about 1 g/ft³ to about 20 g/ft³ and the Fe loadings are from about 1 g/ft³ to about 20 g/ft³; and

wherein the Fe-activated Rh is supported on a OSM.

6. The system of claim 5, wherein the Rh loadings are about 3 g/ft³.

7. The system of claim 5, wherein the Fe loadings are less than about 7 g/ft³.

8. The catalyst system of claim 5, wherein the Fe is present at about 7% (w/w).

9. The catalyst system of claim 5, wherein the Rh is present at less than about 0.5% (w/w).

10. The catalytic system of claim 5, wherein the OSM comprising one selected from the group consisting of Ce, Zr, Nd, Pr, Y, and combinations thereof.

11. The catalytic system of claim 5, wherein the OSM comprising a Ce—

Zr oxide.

12. The catalytic system of claim 5, wherein the OSM comprising a Ce—

Zr oxide having a fluorite phase.

13. The catalytic system of claim 5, wherein the Fe-activated Rh is applied at a loading of less than about 10 g/ft³.

14. The catalytic system of claim 5, wherein the Fe-activated Rh is applied at a loading of greater than about 3 g/ft₃.