Degussa Aktiengesellschaft

Degussa - Huls Ag

Wilfried M&uuml;ller

Thomas Kreuzer

Egbert Lox

Rainer Domesle

Wolfgang Strehlau

Harald Klein

J&uuml;rgen Leyrer

Klaus Ostgathe

A catalyst for purifying exhaust gases of a diesel engine. The catalyst contains two functional layers superimposed on an inert supporting body, whereby the first layer, which is situated directly on the supporting body, has a nitrogen oxide storage function and the second layer, which is in direct contact with the exhaust gas, has a catalytic function. The second functional layer additionally has a hydrocarbon-storage function and its catalytic function is provided by catalytically active noble metals of the platinum group which are deposited in highly dispersed form on finely divided, acidic carrier materials. Nitrogen oxides in the oxygen-rich exhaust gas of a diesel engine can be converted with optimal utilization of the reductive constituents contained in the exhaust gas. For this purpose, no reducing agents going beyond the reductive components (carbon monoxide and hydrocarbons) which are contained as a consequence of incomplete combustion need to be added to the exhaust gas. Nevertheless, rates of conversion in respect of the nitrogen oxides are obtained, averaged over practical driving cycles, which lie distinctly above the rates of conversion of conventional reduction catalysts.

Catalyst for cleaning up the exhaust gases of a diesel engine

A catalyst system for the treatment of exhaust gases from a diesel engine includes a first and a second catalyst reducing catalyst arranged in series in an exhaust gas treatment system. The first catalyst is located near the engine in a region of the exhaust gas treatment system in which the exhaust gas temperature reaches temperatures of more than 200&deg; C. under full engine load. The second catalyst is located further from the engine in a region of the exhaust gas treatment system in which the exhaust gas temperature reaches a maximum of 500&deg; C. under full engine load. The maximum nitrogen oxides reduction in the first catalyst takes place at a lower temperature than the maximum nitrogen oxides reduction in the second catalyst.

Catalyst system for the treatment of exhaust gases from diesel engines

Growing community of inventors

Karben, Germany

Wilfried Müller

Growing community of inventors

Karben, Germany

Wilfried M&uuml;ller

Wilfried Müller