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US 10,245,582 B2Granted
Zeolite catalyst containing metals
AssigneeJohnson Matthey Public Limited Company
InventorsJoseph Michael Fedeyko, Hai-Ying Chen
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Abstract
Provided is catalyst material useful for the selective catalytic reduction of NOx in lean burn exhaust gas, wherein the catalyst material is a hydrothermally stable, low SAR aluminosilicate zeolite loaded with a synergistic combination of one or more transition metals, such as copper, and one or more alkali or alkaline earth metals, such as calcium or potassium.
Claims15
A catalyst composition comprising:
- a. an aluminosilicate zeolite material comprising silica and alumina in a CHA framework and having a silica-to-alumina mole ratio (SAR) of about 10 to about 25;
- b. about 1 to about 5 weight percent of a base metal (“BM”), based on the total weight of the zeolite material, wherein said base metal disposed in said zeolite material as free and/or extra-framework exchanged metal;
- c. an alkali or alkaline earth metal (collectively “AM”) disposed in said zeolite material disposed in said zeolite material as free and/or extra-framework exchanged metal,
- wherein the BM and AM are present, respectively, in a molar ratio of about 15:1 to about 1:1,
- wherein the alumina contains aluminum (Al) that is part of the zeolite framework and the catalyst composition has a (BM+AM):Al mole ratio of about 0.1 to about 0.4, and
- wherein AM is calcium;
- and
- d. about 1 to about 10 weight percent of cerium in said zeolite material, based on the total weight of the zeolite, wherein said cerium is present in a form selected from exchanged cerium ions, monomeric ceria, oligomeric ceria, and combinations thereof, provided that said oligomeric ceria has a particle size of less than 5 μm.
5 more elements
Dependencies are inferred from the claim text.