Use of a palladium/platinum/zeolite-based catalyst as passive nitrogen oxide adsorber for purifying exhaust gas
AssigneeUmicore AG & Co. KG
InventorsChristoph HENGST, Michael LENNARTZ, Frank-Walter SCHUETZE
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Abstract
The invention relates to the use of a catalyst as a passive nitrogen oxide adsorber, which has a carrier substrate, a zeolite, palladium, and platinum, wherein the palladium is provided in a quantity of 0.01 to 10 wt. %, based on the sum of the weights of zeolite, platinum, and palladium and calculated as a palladium metal, and platinum in a quantity of 0.1 to 10 wt. %, based on the weight of the palladium and calculated as a platinum metal. The invention also relates to the use of said catalyst in connection with a SCR catalyst in an exhaust gas system.
Claims13
Use of a catalyst comprising a carrier substrate of length L and a coating A comprising a zeolite, palladium and platinum, wherein palladium is present in amounts of 0.01 to 10 wt. %, based on the sum of the weights of zeolite, platinum and palladium, and is calculated as palladium metal, and platinum is present in amounts of 0.1 to 10 wt. %, based on the weight of palladium, and is calculated as platinum metal, as a passive nitrogen oxide adsorber that stores nitrogen oxides in a first temperature range and releases them again in a second temperature range, wherein the second temperature range is at higher temperatures than the first temperature range.
Dependencies are inferred from the claim text.