Nano-sized functional binder
Described are catalytic articles comprising a substrate having a washcoat on the substrate, the washcoat containing a catalytic component having a first average (D50) particle size and a functional binder component having a second average (D50) particle size in the range of about 10 nm to about 1000 nm, wherein the ratio of the first average (D50) particle size to the second average (D50) particle size is greater than about 10:1. The catalytic articles are useful in methods and systems to purify exhaust gas streams from an engine.
1. A catalytic article for purification of exhaust gases of combustion engines comprising a substrate having a washcoat on the substrate, the washcoat containing a catalytic component having a first average (D50) particle size and a functional binder component having a second average (D50) particle size of about 10 nm to about 1000 nm,
wherein the ratio of the first average (D50) particle size to the second average (D50) particle size is greater than about 10:1, and
wherein the washcoat has a porosity in the range of about 10% to about 50% as measured by scanning electron microscopy (SEM).
2. The catalytic article of claim 1 , wherein the functional binder component has a structure selected from the group consisting of zeolite, Perovskite, spinel, composite, and combinations thereof.
3. The catalytic article of claim 1 , wherein the functional binder comprises an oxide selected from the group consisting of transition metal oxide, a rare-earth metal oxide, and combinations thereof.
4. The catalytic article of claim 3 , wherein the transition metal oxide comprises an oxide selected from the group consisting of zirconium oxide, copper oxide, nickel oxide, iron oxide, manganese oxide, and combinations thereof.
5. The catalytic article of claim 3 , wherein the rare-earth metal oxide comprises an oxide selected from the group consisting of cerium oxide, lanthanum oxide, neodymium oxide, yttrium oxide, praseodymium oxide, and combinations thereof.
6. The catalytic article of claim 2 , wherein the composite comprises a solid solution ceria/zirconia having the general formula Ce 0.5 Zr 0.5 O 2 .
7. The catalytic article of claim 1 , wherein the washcoat has porosity in the range of about 20% to about 30%.
8. The catalytic article of claim 1 , wherein the catalytic component comprises a particle size distribution of d10>1.0 μm, d50 is about 3 μm to about 5 μm, and d90 is about 9 μm to about 13 μm.
9. The catalytic article of claim 1 , wherein the catalytic component is selected from the group consisting of an SCR catalyst, a TWC catalyst, a diesel oxidation catalyst (DOC), or a catalyzed soot filter (CSF).
10. The catalytic article of claim 1 , wherein the catalytic component comprises a high surface area metal oxide support and a component selected from the group consisting of a platinum group metal (PGM), a base metal (BM), an oxygen storage component (OSC), a molecular sieve, and combinations thereof.
11. The catalytic article of claim 10 , wherein the high surface area metal oxide support comprises alumina and the functional binder comprises a ceria-containing oxygen storage component (OSC), wherein the alumina to OSC ratio by weight is about 0.5 to about 10.0.
12. The catalytic article of claim 1 , wherein the functional binder component comprises less than about 5% of platinum group metal by weight.
13. The catalytic article of claim 1 , wherein the substrate is a honeycomb substrate.
14. The catalytic article of claim 13 , wherein the honeycomb substrate comprises a wall flow filter.
15. The catalytic article of claim 13 , wherein the honeycomb substrate comprises a flow through substrate.
16. The catalytic article of claim 1 , wherein the functional binder component comprises about 0.5 wt. % to about 40 wt. %, on a solids basis, of the washcoat.
17. The catalytic article of claim 16 , wherein the second average (D50) particle size is about 10 to about 40 nm.