Vanadium-free catalyst for selective catalytic reduction and process for it's preparation

US8569199B2 · kind B2 · utility

Assignee

• UMICORE AG & CO. KG · DE

Inventors

• Katja Adelmann · Darmstadt, DE
• Nicola Soeger · Nidderau, DE
• Lothar Mussmann · Offenbach, DE
• Marcus Pfeifer · Mannheim, DE
• Gerald Jeske · Neuberg, DE

Key dates

• Filing date: Sep 17, 2007
• Grant date: Oct 29, 2013
• Expiry date: Jul 13, 2029

Classification

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

Abstract

Selective catalytic reduction with ammonia or a compound that decomposes to ammonia is a known method for the removal of nitrogen oxides from the exhaust gas of primarily lean-burn internal combustion engines. The vanadium-containing SCR catalysts that have long been generally used for this are characterized by a good conversion profile. However, the volatility of vanadium oxide can, at higher exhaust gas temperatures, lead to the emission of toxic vanadium compounds. Zeolite-based SCR catalysts, which are used in particular in discontinuous SCR systems, constitute a very cost-intensive solution for the problem.A method is proposed by which a homogeneous cerium-zirconium mixed oxide is activated for the SCR reaction in a defined manner by the introduction of sulphur and/or transition metal. Using this method, a highly active, ageing-resistant SCR catalyst is provided, which represents a vanadium-free, cost-effective and high-performance alternative to the existing SCR catalysts and is suitable in particular for use in motor vehicles.