Zeolite catalyst containing metal
View Patent ↗A catalyst composition is provided having a zeolite material of a CHA crystal structure and a silica to alumina mole ratio (SAR) of about 10 to about 25 and preferably having a mean crystal size of at least 1.0 microns; and a non-aluminum base metal (M), wherein said zeolite material contains said base metal in a base metal to aluminum ratio (M:Al) of about 0.10 to about 0.24.
1. A catalyst composition comprising
a. a zeolite material having a CHA crystal structure and a silica to alumina mole ratio (SAR) of about 10 to about 25; and
b. a non-aluminum base metal (M), wherein said zeolite material contains said base metal in a base metal to aluminum ratio (M:Al) of about 0.10 to about 0.24.
2. The catalyst of claim 1 wherein said zeolite has a mean crystal size of at least about 1.0 μm.
3. The catalyst of claim 1 wherein said zeolite has a mean crystal size of at about 1.0 μm to about 5.0 μm.
4. The catalyst of claim 1 wherein said zeolite has a mean crystal size of at about 1.5 μm to about 2.5 μm.
5. The catalyst of claim 1 wherein said zeolite has an SAR of about 10 to about 20.
6. The catalyst of claim 1 wherein said zeolite has an SAR of about 15 to about 17.
7. The catalyst of claim 1 wherein said zeolite has a non-phosphorous CHA crystal structure.
8. The catalyst of claim 1 wherein said CHA is a synthetic zeolite.
9. The catalyst of claim 1 having a particle size of about 1 to about 100 microns.
10. The catalyst of claim 1 wherein said base metal is selected from the group consisting of Cr, Ce, Mn, Fe, Co, Ni and Cu.
11. The catalyst of claim 10 , wherein the catalyst has M:Al ratio of about 0.17 to about 0.24.
12. The catalyst of claim 10 , wherein the catalyst has M:Al ratio of about 0.22 to about 0.24.
13. The catalyst of claim 1 , wherein said zeolite material contains about 80 to about 120 grams of Cu per cubit foot of zeolite material.
14. A catalyst produced by depositing copper on a zeolite substrate having a non-phosphorous chabazite crystal structure with a mean crystal size of at least about 0.5 micron and an SAR of about 10 to about 25 to form a catalytic material having a copper to aluminum molecular ratio of about 0.10 to about 0.24.
15. A catalytically active article comprising a monolith substrate containing a catalyst composition according to claim 1 .
16. The catalyst article of claim 15 , wherein the substrate is a wall flow filter and the catalyst composition is within a washcoat applied to the substrate.
17. The catalyst article of claim 15 , wherein the substrate is a flow-through honeycomb and the catalyst composition is within a washcoat applied to the substrate.
18. The catalyst article of claim 15 , wherein substrate is an extruded-type flow through catalyst.
19. A method for reducing NOx in an exhaust gas comprising contacting the gas with a catalyst for a time and temperature sufficient to reduce the level of NOx compounds in the gas, wherein the catalyst is a catalyst composition according to claim 1 .
20. A catalyst article for treating ammonia slip comprising a top layer having a catalyst composition according to claim 1 and an oxidative under-layer comprising a platinum group metal.