Catalyst for removing nitrogen oxides from the exhaust gas of diesel engines

US9095816B2 · kind B2 · utility

Assignee

• UMICORE AG & CO. KG · DE

Inventors

• Paul Spurk · Weiterstadt, DE
• Nicola Soeger · Nidderau, DE
• Elena Mueller · Pfungstadt, DE
• Stephan Malmberg · Frankfurt, DE

Key dates

• Filing date: Nov 14, 2011
• Grant date: Aug 4, 2015
• Expiry date: Jan 2, 2032

Classification

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

Abstract

The invention relates to a catalyst for removal of nitrogen oxides from the exhaust gas of diesel engines, and to a process for reducing the level of nitrogen oxides in the exhaust gas of diesel engines. The catalyst consists of a support body of length L and of a catalytically active coating which in turn may be formed from one or more material zones. The material zones comprise selectively catalytically reductive (SCR-active) mixed oxide consisting of cerium oxide, zirconium oxide, rare earth sesquioxide and niobium oxide and optionally tungsten oxide. In addition, the material zones comprise at least one compound selected from the group consisting of barium oxide, barium hydroxide, barium carbonate, strontium oxide, strontium hydroxide, strontium carbonate, praseodymium oxide, lanthanum oxide, magnesium oxide, mixed magnesium/aluminum oxide, alkali metal oxide, alkali metal hydroxide, alkali metal carbonate and mixtures thereof. Noble metal may optionally also be present in the catalyst.