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. 19, 1998
Filed:
Nov. 29, 1996
Douglas A Dobson, Plymouth, MI (US);
Carolyn Parks Hubbard, Dearborn Heights, MI (US);
William Lewis Watkins, Toledo, OH (US);
Ford Global Technologies, Inc., Dearborn, MI (US);
Abstract
The invention is a nitrogen oxide trap comprising a porous support loaded with 6-15 wt. % strontium oxide and thereon, a mixture of: 0.5-5 wt. % precious metal catalyst selected from platinum, palladium, rhodium or mixtures thereof loaded, 3.5-15 wt. % zirconium and 15-30 wt. % sulfate, where preferably the ratio of zirconium to sulfate ranges from about 1:1 to 1:7; each wt. % being individually based on the weight of the support. The trap may be used in an internal combustion engine exhaust gas catalyst system. During lean-burn operation of the engine the trap sorbs nitrogen oxides (NOx) and releases the nitrogen oxides during decreased oxygen concentration in the exhaust gas, the desorbed NOx being converted to N.sub.2 and O.sub.2.