Layered noble metal-containing exhaust gas catalyst and its preparation

US6294140A · kind A · utility

Assignee

• Degussa AG · DE

Inventors

• Lothar Mussmann · Offenbach, DE
• Dieter Lindner · Hanau, DE
• Michael Harris · Hudson, US
• Thomas Kreuzer · Karben, DE
• Egbert Lox · Hanau, DE

Key dates

• Filing date: Oct 1, 1999
• Grant date: Sep 25, 2001
• Expiry date: Oct 1, 2019

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S502/514
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

A catalyst for treating exhaust gas from an internal combustion engine includes a carrier body coated with an inner layer and an outer layer. The inner layer includes platinum deposited on a first support material and on a first oxygen storage component, and the outer layer includes platinum and rhodium deposited on a second support material and on a second oxygen storage component. The first and second support materials may be the same or different, and may be selected from the group of: silica, alumina, titania, zirconia, mixed oxides or mixtures thereof, and zirconia-rich zirconia/ceria mixed oxide. The first and second oxygen storage components may include ceria-rich ceria/zirconia mixed oxide compounds, optionally including praseodymia, yttria, neodymia, lanthana or mixtures thereof.