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:
Jul. 08, 2008
Filed:
Aug. 05, 2005
Applicant:
Jong-hwan Lee, Rochester Hills, MI (US);
Inventor:
Jong-Hwan Lee, Rochester Hills, MI (US);
Assignee:
GM Global Technology Operations, Inc., Detroit, MI (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B01D 53/56 (2006.01); B01D 53/94 (2006.01);
U.S. Cl.
CPC ...
Abstract
The hydrocarbon-assisted, selective catalytic reduction of NOx constituents in lean-bum engine exhaust is benefited by passage of the exhaust over a staged catalyst bed comprising a first stage of an alumina-supported silver catalyst for oxidation of NO to NOand partial oxidation of added hydrocarbon to an aldehyde. Downstream of the silver catalyst is a second catalyst selected for the reaction of hydrocarbon and aldehyde species with NOto reduce it to nitrogen. Gamma-alumina and BaY zeolite are examples of suitable second stage catalysts.