ASC with platinum group metal in multiple layers
A catalytic article for treating an exhaust gas stream containing particulate matter, hydrocarbons, CO, and ammonia, the article may include: (a) a substrate having an inlet end and an outlet end defining an axial length; (b) a first catalyst coating including: 1) a platinum group metal distributed on a molecular sieve, and 2) a base metal distributed on a molecular sieve; and (c) a second catalyst coating including: 1) a platinum group metal distributed on a molecular sieve, and 2) a base metal distributed on a molecular sieve.
1. A catalytic article for treating an exhaust gas stream containing particulate matter, hydrocarbons, CO, and ammonia, the article comprising:
a. a substrate having an inlet end and an outlet end defining an axial length;
b. a first catalyst coating including: 1) a platinum group metal distributed on a molecular sieve, and 2) a base metal distributed on a molecular sieve;
c. a second catalyst coating including: 1) a platinum group metal distributed on a molecular sieve, and 2) a base metal distributed on a molecular sieve,
wherein
a. the first catalyst coating extends from the outlet end toward the inlet end, covering less than the entire axial length of the substrate; and
b. the second catalyst coating extends from the inlet end toward the outlet end, covering less than the entire axial length of the substrate and overlapping a portion of the first catalyst coating.
2. The catalytic article of claim 1 , wherein the molecular sieve in the first and/or second coating comprises a zeolite.
3. The catalytic article of claim 1 , wherein the base metal in the first and/or second coating comprises copper, iron, or a combination thereof.
4. The catalytic article of claim 1 , wherein the first coating and second coating each comprise platinum distributed on a zeolite and copper distributed on a zeolite.
5. The catalytic article of claim 1 , wherein the first coating includes a higher platinum group metal loading than the second coating.
6. The catalytic article of claim 1 , wherein the first coating and the second coating include an equivalent platinum group metal loading.
7. The catalytic article of claim 1 , wherein first coating comprises a platinum group metal loading of about 0 g/ft 3 to about 10 g/ft 3 , or about 1 g/ft 3 to about 5 g/ft 3 .
8. The catalytic article of claim 1 , wherein the second coating comprises a platinum group metal of about 0 g/ft 3 to about 5 g/ft 3 ; or about 1 g/ft 3 to about 3 g/ft 3 .
9. The catalytic article of claim 1 , wherein the weight ratio of platinum group metal in the first coating to the platinum group metal in the second coating is from about 20:1 to about 1:3; about 20:1 to about 1:1; about 10:1 to about 1:2; about 10:1 to about 1:1; about 6:1 to about 1:1; about 3:1 to about 1:1; or about 3:0.5 to about 1:1.
10. The catalyst article of claim 1 , wherein the first catalyst coating and the second catalyst coating overlap to form three zones, a first zone to primarily remove NOx, a second zone to primarily oxidize ammonia to N 2 , and a third zone to primarily oxidize carbon monoxide and hydrocarbons.
11. The catalyst article of claim 1 , wherein the substrate comprises an extruded SCR.
12. The catalyst article of claim 1 , wherein the substrate comprises an extruded SCR.
13. The catalyst article of claim 1 , wherein the substrate comprises an extruded SCR.
14. An emissions treatment system comprising:
a. a diesel engine emitting an exhaust stream including particulate matter, NOx, and carbon monoxide;
b. an SCR catalyst;
c. a catalytic article comprising:
i. a substrate having an inlet end and an outlet end defining an axial length;
ii. a first catalyst coating including: 1) a platinum group metal distributed on a molecular sieve, and 2) a base metal distributed on a molecular sieve;
iii. a second catalyst coating including: 1) a platinum group metal distributed on a molecular sieve, and 2) a base metal distributed on a molecular sieve; the catalytic article located downstream of the SCR catalyst,
wherein the SCR catalyst and the ASC catalyst are located on a single substrate, and the SCR catalyst is located on an inlet side of the substrate and the ASC catalyst is located on the outlet side of the substrate.
15. A method of reducing emissions from an exhaust stream, comprising contacting the exhaust stream with the catalyst article of claim 1 .
16. A catalytic article for treating an exhaust gas stream containing particulate matter, hydrocarbons, CO, and ammonia, the article comprising:
a. a substrate having an inlet end and an outlet end defining an axial length;
b. a first catalyst coating including: 1) a platinum group metal distributed on a molecular sieve, and 2) a base metal distributed on a molecular sieve;
c. a second catalyst coating including: 1) a platinum group metal distributed on a molecular sieve, and 2) a base metal distributed on a molecular sieve,
wherein
a. the first catalyst coating extends from the outlet end toward the inlet end, covering less than the entire axial length of the substrate; and
b. the second catalyst coating covers the entire axial length of the substrate and overlaps the first catalyst coating.
17. The catalytic article of claim 16 , wherein the molecular sieve in the first and/or second coating comprises a zeolite.
18. The catalytic article of claim 16 , wherein the base metal in the first and/or second coating comprises copper, iron, or a combination thereof.
19. The catalytic article of claim 16 , wherein the first coating and second coating each comprise platinum distributed on a zeolite and copper distributed on a zeolite.
20. The catalytic article of claim 16 , wherein the first coating includes a higher platinum group metal loading than the second coating.
21. The catalytic article of claim 16 , wherein the first coating and the second coating include an equivalent platinum group metal loading.
22. The catalytic article of claim 16 , wherein first coating comprises a platinum group metal loading of about 0 g/ft 3 to about 10 g/ft 3 , or about 1 g/ft 3 to about 5 g/ft 3 .
23. The catalytic article of claim 16 , wherein the second coating comprises a platinum group metal of about 0 g/ft 3 to about 5 g/ft 3 ; or about 1 g/ft 3 to about 3 g/ft 3 .
24. The catalytic article of claim 16 , wherein the weight ratio of platinum group metal in the first coating to the platinum group metal in the second coating is from about 20:1 to about 1:3; about 20:1 to about 1:1; about 10:1 to about 1:2; about 10:1 to about 1:1; about 6:1 to about 1:1; about 3:1 to about 1:1; or about 3:0.5 to about 1:1.
25. A catalytic article for treating an exhaust gas stream containing particulate matter, hydrocarbons, CO, and ammonia, the article comprising:
a. a substrate having an inlet end and an outlet end defining an axial length;
b. a first catalyst coating including: 1) a platinum group metal distributed on a molecular sieve, and 2) a base metal distributed on a molecular sieve;
c. a second catalyst coating including: 1) a platinum group metal distributed on a molecular sieve, and 2) a base metal distributed on a molecular sieve,
wherein
a. the first catalyst coating covers the entire axial length of the substrate; and
b. the second catalyst coating extends from the inlet end toward the outlet end, covering less than the entire axial length of the substrate and overlapping a portion of the first catalyst coating.
26. The catalytic article of claim 25 , wherein the molecular sieve in the first and/or second coating comprises a zeolite.
27. The catalytic article of claim 25 , wherein the base metal in the first and/or second coating comprises copper, iron, or a combination thereof.
28. The catalytic article of claim 25 , wherein the first coating and second coating each comprise platinum distributed on a zeolite and copper distributed on a zeolite.
29. The catalytic article of claim 25 , wherein the first coating includes a higher platinum group metal loading than the second coating.
30. The catalytic article of claim 25 , wherein the first coating and the second coating include an equivalent platinum group metal loading.
31. The catalytic article of claim 25 , wherein first coating comprises a platinum group metal loading of about 0 g/ft 3 to about 10 g/ft 3 , or about 1 g/ft 3 to about 5 g/ft 3 .
32. The catalytic article of claim 25 , wherein the second coating comprises a platinum group metal of about 0 g/ft 3 to about 5 g/ft 3 , or about 1 g/ft 3 to about 3 g/ft 3 .
33. The catalytic article of claim 25 , wherein the weight ratio of platinum group metal in the first coating to the platinum group metal in the second coating is from about 20:1 to about 1:3; about 20:1 to about 1:1; about 10:1 to about 1:2; about 10:1 to about 1:1; about 6:1 to about 1:1; about 3:1 to about 1:1; or about 3:0.5 to about 1:1.