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:
Oct. 10, 2000
Filed:
Aug. 17, 1998
William Lewis Watkins, Toledo, OH (US);
Robert J Kudla, Warren, MI (US);
Mohinder S Chattha, Northville, MI (US);
Ford Global Technologies, Inc., Dearborn, MI (US);
Abstract
The invention is a method of treating exhaust gases generated by an internal combustion engine using a NOx trap in the exhaust gas system. The method comprises locating a nitrogen oxide trap in the exhaust gas passage and cycling the air/fuel ratio of the exhaust gases entering the trap between lean and rich, such that the trap absorbs nitrogen oxides during the lean cycle and desorbs the nitrogen oxides when the concentration of the oxygen in the exhaust gas is lowered as during a rich cycle. The trap comprises: (a) a tri-metal oxides made of aluminum-manganese-zirconium and (b) at least 0.1 wt. % platinum, the wt. % being based on the weight of said tri-metal oxide material. The desorbed nitrogen oxides may be converted over the precious metal to N.sub.2 and O.sub.2 by reductants like hydrocarbons present in the exhaust gas. The invention is also the catalyst trap material.