Chemistry of inorganic compounds – Modifying or removing component of normally gaseous mixture – Mixture is exhaust from internal-combustion engine
Patent
1997-03-10
1999-07-13
Tran, Hien
Chemistry of inorganic compounds
Modifying or removing component of normally gaseous mixture
Mixture is exhaust from internal-combustion engine
4232132, 4232135, 4232391, 423235, 422177, 422171, 60274, 60297, 502208, 502210, 502213, 502305, 502313, B01J 802, B01D 5334
Patent
active
059222956
ABSTRACT:
The invention is a nitrogen oxide trap comprising a porous support of alumina; and loaded thereon materials consisting essentially of particular amounts of: (I) tungstophosphoric acid and (II) precious metal selected from platinum, palladium, rhodium and mixtures thereof. The trap is useful for trapping nitrogen oxides produced in the exhaust gas generated by an internal combustion gasoline engine during lean-burn operation of the engine. The trap releases the nitrogen oxides during decreased oxygen concentration in the exhaust gas. The desorbed NOx may be converted over the precious metal to N.sub.2 and O.sub.2 by reductants like hydrocarbons present in the exhaust gas.
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Chattha Mohinder S.
Hoost Tjenga E.
Kudla Robert J.
Ford Global Technologies Inc.
Melotik Lorraine S.
Tran Hien
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