Exhaust emission treatment device with a sulfur-free catalyst composition

Abstract

A catalyst composition is disclosed comprising a support, a substantially sulfur-free stabilizer and a catalytic metal. Also disclosed is the catalytic converter comprising this new catalyst. Methods of making the catalyst composition and the catalytic converter are also described. The lack of added sulfur combined with basic pH application provide a catalyst with excellent stability for high temperature applications such as close coupled catalysts.

1 . An exhaust emission treatment device, comprising: 
 a shell;    a substrate comprising a catalyst composition, wherein the catalyst composition comprises a catalyst support, a catalytic metal, and a stabilizer comprising less than or equal to 0.1 wt % sulfur based on the total weight of the catalyst composition; and    a support element disposed between the shell and the substrate.    
     
     
         2 . The exhaust emission treatment device of  claim 1 , wherein the stabilizer further comprises a material selected from the group consisting of alkaline earth metals, alkali metals, rare-earth metals, and oxides, complexes, compounds, and combinations comprising at least one of the foregoing stabilizers.  
     
     
         3 . The exhaust emission treatment device of  claim 2 , wherein the stabilizer is selected from the group consisting of barium, lanthanum, and oxides, complexes, compounds, and combinations comprising at least one of the foregoing stabilizers.  
     
     
         4 . The exhaust emission treatment device of  claim 3 , wherein the stabilizer is selected from the group consisting of barium aluminate, barium stabilized aluminate, barium-manganese aluminate, barium-magnesium aluminate, barium-cerium-magnesium aluminate, strontium-lanthanum-manganese aluminate, lanthanum-magnesium aluminate, lanthanum-neodymium-magnesium aluminate, lanthanum stabilized aluminate, lanthanum oxide, lanthanum hydroxide, and complexes, compounds, and combinations comprising at least one of the foregoing stabilizers.  
     
     
         5 . The exhaust emission treatment device of  claim 3 , wherein the stabilizer comprises a material selected from the group consisting of lanthanum compounds and lanthanum complexes.  
     
     
         6 . The exhaust emission treatment device of  claim 5 , wherein the stabilizer further comprises barium lanthanum aluminum oxide, lanthanum aluminate, lanthanum oxide, lanthanum hydroxide, and combinations comprising at least one of the foregoing stabilizers.  
     
     
         7 . The exhaust emission treatment device of  claim 1 , wherein the stabilizer further comprises about 88 wt % to about 96 wt % barium aluminate, about 4 wt % to about 10 wt % of a lanthanum compound, and less than or equal to about 2 wt % aluminum hydroxide.  
     
     
         8 . The exhaust emission treatment device of  claim 1 , wherein the substrate comprises a metal foil.  
     
     
         9 . The exhaust emission treatment device of  claim 1 , wherein the support comprises aluminum oxide.  
     
     
         10 . The exhaust emission treatment device of  claim 1 , wherein the catalytic metal is selected from the group consisting of platinum, palladium, rhodium and combinations comprising one or more of the foregoing catalytic metals.  
     
     
         11 . A method of making a substrate supported catalyst comprising: 
 applying to a substrate a catalyst composition comprising a catalyst support, a catalytic metal, and a stabilizer comprising less than or equal to 0.1 wt % sulfur based on the total weight of the catalyst composition to form a coated substrate, and calcining the coated substrate.    
     
     
         12 . The method of  claim 11  comprising applying the catalyst composition at a pH greater than or equal to about 7.0.  
     
     
         13 . The method of  claim 12  comprising applying the catalyst composition at a pH greater than or equal to about 9.0.  
     
     
         14 . The method of  claim 12 , comprising applying the catalyst composition at a pH greater than or equal to about 10.0.