SCR catalytic converter having improved hydrocarbon resistance

US8926925B2 · kind B2 · utility

Assignee

• UMICORE AG & CO. KG · DE

Inventors

• Nicola Soeger · Nidderau, DE
• Katja Adelmann · Darmstadt, DE
• Michael Seyler · Rodenbach, DE
• Thomas R. Pauly · Lansing, US
• Gerald Jeske · Neuberg, DE

Key dates

• Filing date: Mar 1, 2012
• Grant date: Jan 6, 2015
• Expiry date: Mar 1, 2032

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S502/52712
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

A catalyst for the selective catalytic reduction of nitrogen oxides in diesel engine exhaust gases using ammonia or a precursor compound decomposable to ammonia. The catalyst includes two superposed coatings applied to a support body, of which the first coating applied directly to the support body includes a transition metal-exchanged zeolite and/or a transition metal-exchanged zeolite-like compound, and effectively catalyzes the SCR reaction. The second coating is applied to the first coating to cover it on the exhaust gas side and prevent hydrocarbons having at least three carbon atoms present in the exhaust gas from contacting the first coating, without blocking the passage of nitrogen oxides and ammonia to the first coating. The second coating may be formed from small-pore zeolites and/or small-pore, zeolite-like compounds, and from suitable oxides, especially silicon dioxide, germanium dioxide, aluminum oxide, titanium dioxide, tin oxide, cerium oxide, zirconium dioxide and mixtures thereof.