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:
Aug. 10, 1993
Filed:
Oct. 20, 1992
Srinivas H Swaroop, Painted Post, NY (US);
Raja R Wusirika, Painted Post, NY (US);
Corning Incorporated, Corning, NY (US);
Abstract
Thermally stable Cr-zeolites and Cu-Cr-zeolites, and methods of making same are disclosed. The zeolites have a SiO.sub.2 to Al.sub.2 O.sub.3 mole ratio of about 3 to about 200, and an initial alkali content of less than about about 0.5% by weight based on the alkali oxide. Chromium ions are exchanged into the zeolite to produce Cr-zeolite in which the Cr level is greater than about 0.5% by weight. Copper and chromium ions are provided exchanged on a zeolite to produce Cu-Cr-zeolite. The respective Cr-exchanged zeolites are heat-treated to produce the thermally stable zeolites wherein the BET surface area upon exposure to temperatures of up to about 1000.degree. C. is at least about 50% of the BET surface area of the respective thermally stable zeolites at about room temperature, prior to the exposure to temperatures of up to about 1000.degree. C.