Catalyst for the purification of exhaust gases of internal combustion engines

US4294726A · kind A · utility

Assignee

• Deutsche Gold- und Silber-Scheideanstalt Vormals Roessler

Inventors

• Alfred Bozon · Niederrodenbach, DE
• Edgar Koberstein · Alzenau, DE
• Hans-Dieter Pletka · Alzenau, DE
• Herbert Volker · Hanau, DE
• Eduard Lakatos · Gelnhausen, DE

Key dates

• Filing date: Feb 11, 1980
• Grant date: Oct 13, 1981
• Expiry date: Feb 11, 2000

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02T10/12
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

A three-way catalyst is described for the purification of automobile exhaust gases formed of an active substance of platinum and rhodium and possibly base metal(s) at a certain weight ratio between the two noble metals and at a certain atomic ratio between the noble and the base metal, which are precipitated onto active aluminum oxide containing certain quantities of CeO.sub.2, ZrO.sub.2 and Fe.sub.2 O.sub.3, and whereby the catalyst is obtained by impregnating active aluminum oxide, possibly stabilized with alkaline earth metal, with a solution of cerium, zirconium and iron salt which is thereupon calcined in air at 500.degree.-700.degree. C. and then treated after application of an impregnation of salts of the active substance components in a gas current containing hydrogen at temperatures below 650.degree. C.