Selective catalytic reduction filter devices having NOx storage capabilities

Patent metadata

Field	Value
Publication number	US-10138779-B2
Application number	US-201615350562-A
Country	US
Kind code	B2
Filing date	Nov 14, 2016
Priority date	Nov 14, 2016
Publication date	Nov 27, 2018
Grant date	Nov 27, 2018

Abstract

Selective catalytic reduction filter (SCRF) devices and systems incorporating the same are provided. Systems can include an exhaust gas source, an exhaust gas conduit capable of receiving an exhaust gas stream from the exhaust gas source, and an SCRF device in fluid communication therewith. The SCRF device can include a filter, a selective catalytic reduction (SCR) catalyst disposed on at least portion of the filter, and a NO x storage coating on at least a portion of the filter. The NO x storage coating can include one or more of palladium, barium, or cerium. The NO x storage coating can be biased towards the upstream side of the filter. The NO x storage coating can overlap a portion of the SCR catalyst. The system can further include a water-absorbing alkali oxide. The water-absorbing alkali oxide can be disposed within the SCRF device, the exhaust gas conduit, or in an upstream oxidation catalyst device.

First claim

What is claimed is:

1. An exhaust gas treatment system, the system comprising:
an exhaust gas source;

an exhaust gas conduit capable of receiving an exhaust gas stream from the exhaust gas source;
an oxidation catalyst device in fluid communication with the exhaust gas conduit, wherein the oxidation catalyst device includes a water-absorbing alkali oxide; and
a selective catalytic reduction filter (SCRF) device in fluid communication with the exhaust gas conduit and disposed downstream relative to the oxidation catalyst device, wherein the SCRF device includes:
a filter having an upstream side and a downstream side,
a selective catalytic reduction (SCR) catalyst disposed on at least a portion of the filter, and
a NOx storage coating on at least a portion of the filter.

2. The exhaust gas treatment system of claim 1 , wherein the water-absorbing alkali oxide comprises one or more of lithium, potassium, or sodium.

3. The exhaust gas treatment system of claim 1 , wherein the NOx storage coating comprises one or more of palladium, barium, and cerium.

4. The exhaust gas treatment system of claim 3 , wherein the one or more of palladium, barium, and cerium are present at least partially as an oxide.

5. An exhaust gas treatment system, the system comprising:
an exhaust gas source;
an exhaust gas conduit capable of receiving an exhaust gas stream from the exhaust gas source;

a selective catalytic reduction filter (SCRF) device in fluid communication with the exhaust gas conduit and disposed downstream relative to the exhaust gas source, wherein the SCRF device includes:
a filter having an upstream side and a downstream side,
a selective catalytic reduction (SCR) catalyst disposed on a portion of the filter, and
a NOx storage coating on at least a portion of the filter; and

a water-absorbing alkali oxide disposed upstream from the SCRF device.

6. The exhaust gas treatment system of claim 5 , further comprising an oxidation catalyst device having a catalytically active material in fluid communication with the exhaust gas conduit and disposed upstream from the SCRF device, wherein at least a portion of the water-absorbing alkali oxide is disposed within the oxidation catalyst device.

7. The exhaust gas treatment system of claim 6 , wherein the water-absorbing alkali oxide is deposited on at least a portion of the catalytically active material.

8. The exhaust gas treatment system of claim 7 , further comprising a selective catalytic reduction device in fluid communication with the SCRF device and disposed downstream therefrom.

9. The exhaust gas treatment system of claim 5 , further comprising an oxidation catalyst device which includes the water-absorbing alkali oxide.

10. The exhaust gas treatment system of claim 5 , wherein the NOx storage coating comprises one or more of palladium, barium, and cerium.

11. The exhaust gas treatment system of claim 1 , wherein the NOx storage coating is biased towards to the upstream side of the filter.

12. The exhaust gas treatment system of claim 1 , wherein the NOx storage coating overlaps at least a portion of the SCR catalyst.

13. The exhaust gas treatment system of claim 1 , wherein the SCR catalyst comprises a metal impregnated zeolite.

14. The exhaust gas treatment system of claim 13 , wherein the metal impregnated zeolite comprises one or more of iron, cobalt, copper, vanadium, sodium, barium, titanium, tungsten, and copper.

15. The exhaust gas treatment system of claim 5 , wherein the NOx storage coating is biased towards to the upstream side of the filter.

16. The exhaust gas treatment system of claim 5 , wherein the NOx storage coating overlaps at least a portion of the SCR catalyst.

17. The exhaust gas treatment system of claim 5 , wherein the SCR catalyst comprises a metal impregnated zeolite.

18. The exhaust gas treatment system of claim 17 , wherein the metal impregnated zeolite comprises one or more of iron, cobalt, copper, vanadium, sodium, barium, titanium, tungsten, and copper.

19. The exhaust gas treatment system of claim 10 , wherein the one or more of palladium, barium, and cerium are present at least partially as an oxide.

Assignees

• Gm Global Tech Operations Llc

Inventors

• Mital Rahul
• Qi Gongshin
• Dean Charles
• Solbrig Charles

Classifications

• B01D53/9431

  Processes characterised by a specific device · CPC title

• F01N2510/0684

  having more than one coating layer, e.g. multi-layered coatings · CPC title

• F01N3/2066

  Selective catalytic reduction [SCR] · CPC title

• B01D53/9481

  Catalyst preceded by an adsorption device without catalytic function for temporary storage of contaminants, e.g. during cold start · CPC title

• B01D2255/2042

  Barium · CPC title