Catalyst system for gasoline combustion engines, having three-way catalysts and SCR catalyst

US10022672B2 · kind B2 · utility

Assignee

• UMICORE AG & CO. KG · DE

Inventors

• Jan Schoenhaber · Darmstadt, DE
• Marcus Schmidt · Maumee, US
• Frank Adam · Alzenau, DE

Key dates

• Filing date: Mar 11, 2015
• Grant date: Jul 17, 2018
• Expiry date: Mar 11, 2035

Classification

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

Abstract

The present invention is directed to a catalyst system for the reduction of the harmful exhaust-gas constituents hydrocarbons (THC), carbon monoxide (CO), nitrogen oxides (NOx), and the environmentally detrimental secondary emissions ammonia (NH3) and nitrous oxide (N2O) of combustion engines operated using gasoline and to a corresponding method for exhaust-gas purification. The system is characterized by a particular arrangement of catalysts and is used in the case of engines which are operated with predominantly, on average, stoichiometric air/fuel mixtures. Here, a three-way catalyst produced in accordance with the current prior art is preferably installed in a close-coupled position. In the underfloor position, there is situated an SCR catalyst produced in accordance with the current prior art, followed by a further three-way catalyst produced in accordance with the current prior art. The three-way catalyst in the underfloor region furthermore has a lower oxygen-storing capacity than the close-coupled three-way catalyst.