Aluminum oxide catalyst supports from alumina sols
AssigneeFord Motor Company
InventorsChaitanya K. Narula, William L. H. Watkins, Mordecai Shelef
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Abstract
This invention is directed to a method of providing a channeled substrate with a porous washcoat used as a supporting structure for a catalyst. The substrate is coated with a reactive mixture made of components comprising aluminum alkoxide, water, and acid or the alkoxide in an alcohol. The aluminum alkoxide contains hydrolyzable alkoxy groups and has the chemical formula: Al(OR).sub.3, where R is an alkyl or branched alkyl group of 3 to 6 carbon atoms. The method also includes drying and calcining the coating to form a .gamma.-alumina washcoat.
Claims18
A method of providing a washcoat uniformly comprising oxides uniformly distributed in .gamma.-alumina on a channeled substrate as a supporting structure for an exhaust gas conversion catalyst comprising:
- (a) applying a coating of a reactive mixture, consisting of aluminum alkoxide, at least one salt of barium and cerium, a solvent, and a complexing acid to promote a clear sol to said channeled substrate, said aluminum alkoxide having a chemical formula of Al(OR).sub.3, wherein R comprises an alkyl group of branched alkyl group having between 3 and 6 carbon atoms;
- (b) after removing excess coating from said channels by blowing gas through said channels, hydrolizing said coating;
- (c) drying said coating on said channeled substrate at a temperature sufficient to remove solvent;
- and
- (d) calcining said coating at a temperature to density said coating to form said washcoat comprising .gamma.-alumina.
A method of providing a .gamma.-alumina comprising washcoat on a channeled substrate as a supporting structure for an exhaust gas conversion catalyst comprising:
- (a) applying a coating of a reactive mixture made from aluminum alkoxide, at least one of barium or cerium alkoxide and alcohol vaporizable at or below 100.degree. C. to said channeled substrate, said aluminum alkoxide having a chemical formula of Al(OR).sub.3, wherein R comprises an alkyl group or branched alkyl group having between 3 and 6 carbon atoms;
- (b) removing excess coating from said channels by blowing gas through said channels;
- (c) exposing said coating to water vapor;
- (d) drying said coating on said channeled substrate at a temperature sufficient to remove alcohol and/or water;
- and
- (e) calcining said coating at a temperature to densify said coating to form said washcoat comprising .gamma.-alumina and barium or cerium oxides.
Dependencies are inferred from the claim text.