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:
Feb. 20, 1996
Filed:
Mar. 08, 1993
Frank Ament, Troy, MI (US);
David A Singer, Farmington, MI (US);
General Motors Corporation, Detroit, MI (US);
Abstract
An exhaust system for an internal combustion engine having a primary catalytic converter located downstream of the engine and a hydrocarbon adsorber located downstream of the primary converter. The adsorber comprises a ceramic wall-flow substrate having a zeolite coating, having the ability to selectively adsorb hydrocarbon molecules from exhaust gas, applied to the interior surfaces of the inlet passages of the substrate and a catalytic coating applied to the adjacent surfaces of the walls of the outlet passages of the substrate. The catalyst preferably has a light-off temperature below the desorption temperature of the zeolite. In operation, hydrocarbon is adsorbed by the zeolite following a cold engine start and is held until the zeolite reaches its desorption temperature at which time the hydrocarbon is released and passes through the porous walled substrate for conversion by the catalyst.