Umicore Ag & Co Kg

Ruediger Hoyer

Gerald Jeske

Stephan Eckhoff

Anke Schuler

Elena Mueller

Thomas Utschig

Ulrich Goebel

Michael Schiffer

Thomas R Pauly

Stefan Franoschek

Thomas Kreuzer

Marcus Pfeifer

Frank-Walter Schuetze

Franz Dornhaus

Alfons Baiker

Wilfried Mueller

Michael Seyler

Anke Woerz

Fei Wen

Marek Maciejewski

Ina Grisstede

Masaya Hanzawa

Meike Wittrock

Jan-Dierk Grunwaldt

Friedemann Rohr

Maria Cristina Casapu

Aflons Baiker

Benjamin Betz

Susanne Philipp

The present invention relates to a catalyst which comprises a carrier substrate of length L, which extends between a first end face a and a second end face b, and catalytically active material zones A, B and C of different composition, wherein&#x2014;material zone A comprises palladium or palladium and platinum with a weight ratio of Pd:Pt&#x3e;1, and cerium oxide, &#x2014;material zone B comprises platinum or platinum and palladium with a weight ratio of Pt:Pd&#x3e;1, and cerium oxide and/or cerium/zirconium mixed oxide, and&#x2014;material zone C comprises platinum or platinum and palladium with a weight ratio of Pt:Pd&#x3e;1, and a carrier oxide, and wherein&#x2014;material zone B is arranged above material zone A, and&#x2014;material zone C is arranged above material zone B, and, starting from the second end face b of the carrier substrate, extends over a length of up to 60% of the length L. The invention also relates to a catalyst arrangement containing said catalyst.

Nitrogen oxide storage catalyst

The invention relates to a catalyst system for reducing nitrogen oxides, which comprises a nitrogen oxide storage catalyst and an SCR catalyst, wherein the nitrogen oxide storage catalyst consists of at least two catalytically active washcoat layers on a supporting body, wherein a lower washcoat layer A contains cerium oxide, an alkaline earth compound and/or alkali compound, as well as platinum and palladium, and an upper washcoat layer B, which is arranged over the washcoat layer A, contains cerium oxide, platinum and palladium, and no alkali compound and no alkaline earth compound. The invention also relates to a method for converting NOx in exhaust gases of motor vehicles that are operated by means of engines that are operated in a lean manner.

Catalyst system for reducing nitrogen oxides

The present invention relates to a nitrogen oxide storage catalyst composed of at least two catalytically active washcoat layers on a support body, wherein a lower washcoat layer A comprises cerium oxide, an alkaline earth metal compound and/or an alkali metal compound, and platinum and palladium, and an upper washcoat layer B disposed atop the washcoat layer A comprises cerium oxide, platinum and palladium, and no alkali metal or alkaline earth metal compound, and to a method of converting NOin exhaust gases from motor vehicles which are operated with lean-burn engines.

Catalyst for reduction of nitrogen oxides

The present invention relates to a catalyst for the removal of carbon monoxide and hydrocarbon from the exhaust gas of lean-operated internal combustion engines on a supporting body, which bears platinum and/or palladium on one or more refractory carrier materials and also contains cerium oxide and which, after reductive treatment at 250&#xb0; C. and after CO adsorption, is characterized by certain peaks in Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS), and also relates to the use thereof for removing carbon monoxide and hydrocarbon from the exhaust gas of lean-operated internal combustion engines.

Catalyst for the oxidation of CO and HC at low temperatures

The present invention relates to a nitrogen oxide storage catalyst composed of at least two catalytically active coatings on a support body, wherein a lower coating A contains cerium oxide, and platinum and/or palladium, but no alkaline earth metal compound, and an upper coating B which is disposed above coating A contains an alkaline earth metal compound, a basic mixed magnesium-aluminum oxide, and platinum and palladium, and to a method for converting NOin exhaust gases of motor vehicles which are operated with lean-burn engines.

Catalyst for reducing nitrogen oxides

The present invention relates to a catalyst system for treatment of diesel exhaust gas, comprising, in flow direction of the exhaust gas,

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The invention relates to a method for removing carbon monoxide and hydrocarbons from the exhaust gas of lean-burn internal combustion engines, said exhaust gas being passed over a catalyst which contains platinum supported on one or more refractory supporting materials, pure cerium oxide, and optionally an additional noble metal selected from the group consisting of platinum, palladium and rhodium, wherein the pure cerium oxide is in close contact with the noble metal.

Method for removing carbon monoxide and hydrocarbons from the exhaust gas of lean-burn internal combustion engines

The present invention relates to a regulating strategy for a special catalytic converter for exhaust-gas aftertreatment. The catalytic converter concept is distinguished in that at least two nitrogen oxide storage catalytic converters are used in the exhaust section of a vehicle. The first, possibly close-coupled unit is followed by one or more nitrogen oxide storage catalytic converters, which are possibly situated in the underbody of the vehicle. The nitrogen oxide storage catalytic converters are then regenerated as a function of the exceedance of nitrogen oxide threshold vales downstream thereof.

Regulating strategy for a catalytic converter concept for exhaust-gas aftertreatment having a plurality of nitrogen oxide storage catalytic converters

A nitrogen oxide storage catalyst is provided, which has two catalytically active coatings on a support body. The lower coating applied directly to the support body has a nitrogen oxide storage function and includes platinum as a catalytically active component applied to a homogeneous magnesium-aluminum mixed oxide in combination with a nitrogen oxide storage material, in which a nitrogen oxide storage component is likewise present and applied to a homogeneous magnesium-aluminum mixed oxide. The second layer is notable for three-way catalytic activity, and includes palladium applied to aluminum oxide and barium oxide or strontium oxide, but no platinum.

Nitrogen oxide storage catalytic converter for use in a motor vehicle in a close-coupled position

Nitrogen oxide storage catalysts are used to remove the nitrogen oxides present in the lean exhaust gas of lean-burn engines. As a result of the stress due to high temperatures in vehicle operation, they are subject to thermal aging processes which affect both the nitrogen oxide storage components and the noble metals present as catalytically active components. The present invention provides a process with which the catalytic activity of a nitrogen oxide storage catalyst which comprises, in addition to platinum as a catalytically active component, basic compounds of strontium and/or barium on a support material comprising cerium oxide, said catalytic activity being lost owing to the thermal aging process, can be at least partly restored. The two-stage process is based on the fact that strontium and/or barium compounds formed during the thermal aging with the support material, which also comprise platinum, are recycled to the catalytically active forms by controlled treatment with specific gas mixtures.

Dual-stage method for the reactivation of thermally aged nitrogen oxide storage catalysts

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Alzenau-Hoerstein, Germany

Ruediger Hoyer