The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 10, 2006
Filed:
Dec. 26, 2002
Pascaline H. Tran, Holmdel, NJ (US);
Xinsheng Liu, Edison, NJ (US);
James M. Chen, North Brunswick, NJ (US);
Gerard D. Lapadula, Piscataway, NJ (US);
Howard Furbeck, Hamilton, NJ (US);
Pascaline H. Tran, Holmdel, NJ (US);
Xinsheng Liu, Edison, NJ (US);
James M. Chen, North Brunswick, NJ (US);
Gerard D. Lapadula, Piscataway, NJ (US);
Howard Furbeck, Hamilton, NJ (US);
Engelhard Corporation, Iselin, NJ (US);
Abstract
The present invention is directed to a metal-promoted zeolite beta catalyst useful in the selective catalytic reduction of nitrogen oxides with ammonia in which the zeolite beta is pre-treated so as to provide the zeolite with improved hydrothermal stability. The stabilized beta zeolite is provided by incorporating into the zeolite structure non-framework aluminum oxide chains. The aluminum oxide chains can be incorporated into the zeolite structure by a unique steaming regimen or by treatment with rare earth metals, such as cerium. The treatment process is unlike well-known methods of dealuminizing zeolites for the purpose of increasing the silica to alumina ratio. In the present invention, the non-framework aluminum oxide is characterized by FT-IR by a peak at 3781±2 cm, which when present, stabilizes the zeolite against further dealumination such as under oxidizing and harsh hydrothermal conditions.