Process for absorbing and desorbing nitrogen oxides in exhaust gases
AssigneeDaimler-Benz Aktiengesellschaft
InventorsBernd Krutzsch, Andrea Seibold, Leonhard Walz, Walter Boegner, Martina Heinau, Martin Hartweg, Brigitte Konrad
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Abstract
A material and a process for adsorbing and desorbing nitrogen oxides in exhaust gas systems of engines running on a lean mixture, which does not require a prior oxidation step, wherein a mixed oxide which has an oxygen-rich orthorhombic structure is used which changes to an oxygen-poor tetragonal structure as a function of temperature.
Claims6
A process for adsorbing and desorbing nitrogen oxides in exhaust gases of an internal combustion engine of a motor vehicle operating on a lean mixture comprising the steps of adsorbing and desorbing the nitrogen oxides with a material comprising a mixed oxide containing a d element,
- wherein the mixed oxide has an oxygen-rich orthorhombic structure which changes into an oxygen-poor tetragonal structure as a function of temperature, and
- whereby the mixed oxide containing the d element binds the nitrogen oxides without a prior oxidation step during adsorption.
Dependencies are inferred from the claim text.