Nano-sized functional binder

Abstract

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 .- 18 . (canceled) 
     
     
         19 . A method of purifying exhaust gases, the method comprising contacting the exhaust gases with 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).   
     
     
         20 . A method of preparing a washcoat, the method comprising
 providing a first catalyst component, optionally milled, having a first particle size distribution of d 10 >about 1.0 μm, d 50 about 3 μm to about 5 μm, and d90 about 9 μm to about 13 μm;   providing a second catalyst component, optionally milled, having a second particle size distribution of d 10 >about 1.0 μm, d 50  about 3 μm to about 5 μm, and d 90  about 9 μm to about 13 μm;   mixing the first catalyst component and the second catalyst component in an aqueous solution to provide a catalytic component having a first average (D50) particle size; and   combining the aqueous solution of the catalytic component with a functional binder component to provide a washcoat, wherein the functional binder component has 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.   
     
     
         21 . The method of  claim 20 , wherein the first catalyst component comprises a high surface area metal oxide support. 
     
     
         22 . The method of  claim 21 , wherein the second catalyst component comprises an oxygen storage component (OSC). 
     
     
         23 . The method of  claim 21 , wherein the high surface area metal oxide support comprises alumina. 
     
     
         24 . The method of  claim 22 , wherein the high surface area metal oxide support comprises alumina and wherein the ratio of alumina to OSC is about 0.5 to about 10.0.