Methods and systems for a diesel oxidation catalyst

Patent metadata

Field	Value
Publication number	US-11143073-B2
Application number	US-202016785067-A
Country	US
Kind code	B2
Filing date	Feb 7, 2020
Priority date	Mar 22, 2017
Publication date	Oct 12, 2021
Grant date	Oct 12, 2021

Abstract

Systems are provided for a diesel oxidation catalyst. In one example, the diesel oxidation catalyst comprises a washcoat with different catalytically active portions for reacting with one or more of carbon containing compounds and NOx. The diesel oxidation catalyst is located upstream of a particulate filter in an exhaust passage.

First claim

The invention claimed is:

1. A system comprising:
a catalyst located in an exhaust passage of an engine driven vehicle, where the catalyst comprises a washcoat having a zirconium oxide support, one or more base metal oxides and at least a precious metal oxide, wherein the one or more base metal oxides and the precious metal oxide are on different portions of the zirconium oxide support, wherein the base metal oxides comprise Mn, Cu, and Ce in a weight percent ratio of 20:7.5:15;
a particulate filter located in a position of the exhaust passage downstream of the catalyst relative to a direction of exhaust gas flow; and
a controller with computer readable instructions stored thereon that enable the controller to:
actively regenerate the particulate filter via adjusting actuators to increase an exhaust gas temperature to a temperature greater than a threshold temperature, where an exhaust gas flow rate is outside of a range between upper and lower threshold flow rates and adjust the exhaust gas flow rate to a rate between the upper and lower threshold exhaust gas flow rates.

2. The system of claim 1 , wherein the threshold temperature is a threshold NO 2 facilitated regeneration temperature and where the threshold NO 2 facilitated regeneration temperature is lower than a threshold oxygen facilitated regeneration temperature.

3. The system of the claim 2 , wherein the threshold NO 2 facilitated regeneration temperature is determined based on a regeneration temperature of the particulate filter in the presence of NO 2 being greater than a threshold amount of NO 2 , and where the threshold oxygen facilitated regeneration temperature is based on a regeneration temperature of the particulate filter in the presence of an amount of NO 2 being less than the threshold amount of NO 2 .

4. The system of claim 1 , wherein adjusting the actuators to increase the exhaust gas temperature includes adjusting a fuel injector positioned in the exhaust passage to inject fuel and provide exothermic heat to actively heat the particulate filter.

5. A system comprising:
a catalyst located in an exhaust passage of an engine driven vehicle, where the catalyst comprises a washcoat having a zirconium oxide support, one or more base metal oxides and a palladium oxide, where the palladium oxide is contained in an upstream portion of the catalyst relative to a direction of exhaust gas flow, and wherein the one or more base metal oxides are contained in a downstream portion of the catalyst relative to the direction of exhaust gas flow;
a particulate filter located in a position of the exhaust passage downstream of the catalyst relative to the direction of exhaust gas flow; and
a controller with computer readable instructions stored thereon that enable the controller to:
actively regenerate the particulate filter via adjusting actuators to increase an exhaust gas temperature to a temperature greater than a threshold temperature and adjust an exhaust gas flow rate to a rate between upper and lower threshold exhaust gas flow rates.

6. The system of claim 5 , wherein the threshold temperature is a threshold NO 2 facilitated regeneration temperature, and where the threshold NO 2 facilitated regeneration temperature corresponds to the regeneration occurring in a presence of an amount of NO 2 greater than a threshold NO 2 regeneration amount.

7. The system of claim 5 , wherein adjusting the actuators to increase the exhaust gas temperature includes adjusting a fuel injection amount following combustion to increase the exhaust gas temperature, wherein the fuel injection amount is provided by a first fuel injector that is coupled to a combustion chamber of the engine driven vehicle.

8. The system of claim 7 , wherein adjusting the actuators to increase the exhaust gas temperature includes adjusting a second fuel injector positioned in the exhaust passage to inject fuel and provide exothermic heat to actively heat the particulate filter.

9. The system of claim 5 , wherein adjusting the actuators to increase the exhaust gas temperature includes adjusting an EGR valve to a more closed position.

10. The system of claim 5 , wherein the regeneration is facilitated by NO 2 when an amount of NO 2 produced by an engine and the catalyst is greater than a threshold NO 2 regeneration amount.

11. The system of claim 5 , wherein the one or more base metal oxides are in a range of 15 to 75 weight percent of the washcoat.

12. The system of claim 5 , wherein generating NO 2 includes flowing exhaust gas through the catalyst, where the exhaust gas flows at an exhaust gas flow rate between upper and lower exhaust gas thresholds, and where the exhaust gas temperature is greater than 200° C.

13. A system comprising:
a catalyst located in an exhaust passage of an engine driven vehicle, where the catalyst comprises a washcoat having a zirconium oxide support, and at least a manganese oxide and a palladium oxide;
a particulate filter located in a position of the exhaust passage downstream of the catalyst relative to a direction of exhaust gas flow; and
a controller with computer readable instructions stored thereon that enable the controller to:
regenerate the particulate filter without adjusting engine operating parameters during a first mode;
facilitate the particulate filter regeneration with oxygen by adjusting the engine operating parameters to increase an exhaust gas temperature by a first magnitude during a second mode, where an exhaust gas flow rate is lower than a lower threshold flow rate; and
facilitate the particulate filter regeneration with NO 2 by adjusting the engine operating parameters to increase the exhaust gas temperature by a second magnitude during a third mode, where the NO 2 is produced by the catalyst located upstream of the particulate filter, where the exhaust gas flow rate is within a range between the lower threshold flow rate and an upper threshold flow rate, and wherein the first magnitude is greater than the second magnitude.

14. The system of claim 13 , wherein the palladium oxide is positioned on an upstream portion of the zirconium oxide support relative to a direction of exhaust gas flow, and wherein the manganese oxide is positioned on a downstream portion of the zirconium oxide support relative to the direction of exhaust gas flow.

15. The system of claim 13 , wherein the particulate filter regeneration during the second mode includes initiating active controls configured to adjust the engine operating parameters to increase the exhaust gas temperature by the first magnitude, wherein increasing the exhaust gas temperature by the first magnitude corresponds to increasing the exhaust gas temperature to a temperature greater than a threshold oxygen facilitated regeneration temperature, where the threshold oxygen facilitated regeneration temperature is equal to 600° C., and where an amount of NO 2 at the particulate filter is less than a threshold NO 2 regeneration amount.

16. The system of claim 15 , wherein initiating the active controls includes one or more of decreasing an EGR flow rate, increasing a fuel injection pressure, increasing a fuel injection volume, decreasing an air/fuel ratio, increasing manifold pressure, and retarding a fuel injection.

17. The system of claim 13 , wherein the particulate filter regeneration during the third mode includes initiating active controls configured to adjust the engine operating parameters to increase the exhaust gas temperature by the second magnitude, wherein increasing the exhaust gas temperature by the second magnitude corresponds to increas

Assignees

• Ford Global Tech Llc

Inventors

• Dobson Douglas Allen
• Chanko Timothy Brian
• Lambert Christine Kay

Classifications

• B01D46/82

  with catalysts · CPC title

• B01D2255/1023

  Palladium · CPC title

• B01D2255/2073

  Manganese · CPC title

• F02D41/029

  the exhaust gas treating apparatus being a particulate filter · CPC title

• B01D53/9477

  with catalysts positioned on separate bricks, e.g. exhaust systems · CPC title