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:
Jun. 13, 2000
Filed:
Mar. 20, 1998
Jordan K Lampert, Metuchen, NJ (US);
Michel Deeba, North Brunswick, NJ (US);
Robert J Farrauto, Westfield, NJ (US);
Engelhard Corporation, Iselin, NJ (US);
Abstract
A catalyzed hydrocarbon trap material washcoat (20) used in a trap (10), which may be placed downstream of a conventional catalyst member (28), is useful for treating internal combustion engine (22) exhaust. Trap (10) traps hydrocarbons during cold operation periods and releases them for oxidation during higher-temperature operating periods. The material comprises palladium and silver dispersed on a high surface area metal oxide support and a zeolite material such as one or more of ZSM-5, Beta, Y, and other suitable zeolites. The trap material is efficiently made by combining in a single vessel the zeolite, the metal oxide support, and aqueous solutions of a palladium compound and a silver compound. Surprisingly, the intimate combination of silver with the palladium does not adversely affect catalytic efficiency of the palladium and provides advantageous results in enhancing catalytic oxidation of hydrocarbons desorbed from the trap (10) and coke which forms thereon.