Sulfur tolerant alumina catalyst support
AssigneeW. R. Grace & Co.-Conn.
InventorsManoj Mukund Koranne, James Neil Pryor, David Monroe Chapman, Rasto Brezny
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Abstract
The present invention is directed to an improved catalyst support and to the resultant catalyst suitable for treating exhaust products from internal combustion engines, especially diesel engines. The support of the present invention is a structure comprising alumina core particulate having high porosity and surface area, wherein the structure has from about 1 to about 40 weight percent silica in the form of cladding on the surface area of said alumina core. The resultant support has a normalized sulfur uptake (NSU) of up to 15 μg/m2.
Claims30
A structure comprising alumina core particulate having high porosity of at least about 0.2 cc/g, a surface area of greater than 20 m2/g and having silica cladding on the surface area of said alumina core, wherein the structure has from about 1 to about 40 weight percent silica and has a normalized sulfur uptake (NSU) of up to 15 μg/m2.
A process for forming an alumina particulate structure useful as a support component for emission control noble metal catalysts comprising forming an aqueous slurry comprising from 5 to 50 weight percent of alumina particulate;
- heating said slurry to a temperature of 50 to 100° C.;
- contacting said slurry with an aqueous solution having from 5 to 30 weight percent of a water-soluble silicate to form a mixture thereof;
- maintaining said mixture at a temperature of 50° to 100° C. for a period of from 1 to 120 minutes;
- substantially uniformly adding a water-soluble acid to said mixture to achieve a pH of 7.5 over a period of from 5 to 240 minutes from commencement of the acid addition and any further amount of acid sufficient to cause the resultant mixture to have a pH of from 5 to 8;
- and separating and recovering a dried powder product comprising a high surface area alumina core having from 1 to 40 weight percent of silica in the form of a cladding thereon.
Dependencies are inferred from the claim text.