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:
May. 13, 2014
Filed:
Aug. 17, 2009
Yasuyuki Takamitsu, Yamaguchi, JP;
Yukio Ito, Yamaguchi, JP;
Yasuyuki Takamitsu, Yamaguchi, JP;
Yukio Ito, Yamaguchi, JP;
Tosoh Corporation, Yamaguchi, JP;
Abstract
A subject for the invention is to provide a highly heat-resistant SCR catalyst which has an NOx reduction percentage of 40% or higher at 200° C. after a hydrothermal durability treatment. The invention relates to use of β-type zeolite which has an SiO/AlOmolar ratio of 20 or higher but less than 30 and a crystallite diameter before a hydrothermal durability treatment of 20 nm or larger, shows a change in crystallite through the hydrothermal durability treatment of less than 10%, and has a fluorine content lower than 0.1%. The β-type zeolite can be crystallized from a liquid reaction mixture containing a secondary and/or a tertiary alkylamine having 5 or more carbon atoms.