Catalyst design for heavy-duty diesel combustion engines

摘要

Disclosed are washcoats, coated substrates formed from such washcoats, and catalytic converters for use in diesel applications, such as heavy duty diesel applications. Methods of preparing the coated substrates are also disclosed.

主权项

1. A coated substrate comprising:
a substrate; a first washcoat layer comprising:
boehmite particles; anda first catalytically active material comprising platinum and palladium in a weight ratio of 10:1 platinum:palladium to 100:1 platinum:palladium, or comprising platinum and no palladium; and a second washcoat layer comprising:
boehmite particles; anda second catalytically active material comprising:
i. platinum and palladium in a weight ratio of 1:2 platinum:palladium to 8:1 platinum:palladium;ii. two or more catalytically active materials which together comprise platinum and palladium in a weight ratio of 1:2 platinum:palladium to 8:1 platinum:palladium; oriii. palladium and no platinum.