Solid for storing/releasing nitrogen oxides as well as nitrogen oxide storage catalyst

US6309617A · kind A · utility

Assignee

• Dornier GmbH · DE

Inventors

• Renato Andorf · Meckenbeuren, DE
• Carsten Plog · Markdorf, DE
• Guido Schaeffner · Ravensburg, DE

Key dates

• Filing date: Jul 10, 1998
• Grant date: Oct 30, 2001
• Expiry date: Jul 10, 2018

Classification

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

Abstract

An Ag-containing solid, such as Ag.sub.2 O, Ag.sub.2 CO.sub.3, and AgOH, is used for storing/releasing nitrogen oxides in an exhaust gas from an engine during controlled cycling of the .lambda.-value of the exhaust gas. The nitrogen oxides are stored at .lambda.-values of the gas greater than 1 in the Ag-containing solid and the nitrogen oxides are released at .lambda.-values of the gas less than or equal to 1 from the Ag-containing solid. The Ag-containing solid may include a precious metal or a microporous carrier, for example, ZrO.sub.2, SiO.sub.2, TiO.sub.2, Si--Al mixed oxide, and zeolites.