NOx trap catalyst for lean burn engines

Details NOx trap catalyst for lean burn engines NOx trap catalyst for lean burn engines

1998-08-17

2000-10-10

Dunn, Tom

Chemistry of inorganic compounds

Modifying or removing component of normally gaseous mixture

Nitrogen or nitrogenous component

4232132, 4232135, 423235, 502308, 502313, 502324, 502325, B01J 802, B01J 800, B01J 2300, B01J 2332, C01B 2100

Patent

active

061298980

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.

REFERENCES:
patent: 3873469 (1975-03-01), Foster et al.
patent: 3984591 (1976-10-01), Plumat et al.
patent: 4018706 (1977-04-01), Inoue et al.
patent: 4127510 (1978-11-01), Harrison et al.
patent: 4221768 (1980-09-01), Inoue et al.
patent: 4668299 (1987-05-01), Nanao et al.
patent: 4791091 (1988-12-01), Bricker et al.
patent: 4900712 (1990-02-01), Bar-llan et al.
patent: 5049364 (1991-09-01), Yoshimoto et al.
patent: 5130114 (1992-07-01), Igarashi
patent: 5187137 (1993-02-01), Terui et al.
patent: 5200384 (1993-04-01), Funabiki et al.
patent: 5286700 (1994-02-01), Terui et al.
patent: 5389606 (1995-02-01), Face
patent: 5409671 (1995-04-01), Takemoto et al.
patent: 5473887 (1995-12-01), Takeshima et al.
patent: 5610117 (1997-03-01), Horiuchi et al.
patent: 5643542 (1997-07-01), Leyrer et al.
patent: 5727385 (1998-03-01), Hepburn

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