Catalyst – solid sorbent – or support therefor: product or process – Zeolite or clay – including gallium analogs – And additional al or si containing component
Patent
1991-11-08
1993-02-09
Dees, Carl F.
Catalyst, solid sorbent, or support therefor: product or process
Zeolite or clay, including gallium analogs
And additional al or si containing component
4232135, B01J 2930
Patent
active
051853051
ABSTRACT:
A catalyst system for converting NO.sub.x, CO, and HC contained in the exhaust gas from a gasoline-fueled engine controlled to operate under lean-burn conditions (R=0.03-0.9) such that the a ratio of NO.sub.x to HC in the exhaust gas in in the range of 1/3 to 3/1 (i.e., minimum C.sub.3 H.sub.6 of 250 ppm and NO.sub.x of 200-400 ppm). The system comprises a first stage catalyst containing a transition metal-exchanged zeolite (i.e., Cu-ZSM5), and a three-way catalyst for treating the effluent from said first stage catalyst. The second stage catalyst consists of a high surface area alumina support impregnated with an intimate mixture of 0.5-20% lanthana, 0.2-30% palladium, and advantageously an outer washcoat TiO.sub.2.
A method of treating the exhaust gas from a fossil-fueled engine comprising operating the engine under lean-burn conditions while controlling the emission ratio of NO.sub.x /hydrocarbon to be in the range of 1/3 to 3/1; exposing the exhaust gas to a first stage catalyst comprising a copper ion-exchanged ZSM5 zeolite having at least 3% by weight copper; and exposing the effluent from said first stage catalyst to a second stage catalyst comprising an alumina support impregnated with an intimate mixture of 0.5-20% lanthana and 2-30% palladium.
REFERENCES:
patent: 4331644 (1982-05-01), Ritscher
patent: 4791091 (1988-12-01), Bricker et al.
patent: 4934142 (1988-12-01), Hayashi
patent: 5021389 (1991-06-01), Chatta et al.
patent: 5051244 (1991-09-01), Dunne et al.
patent: 5063192 (1991-11-01), Murakami et al.
"Automobile Catalytic Converters", Taylor, Springer, Berlin 1984, p. 107.
"Cu-ZSM-5 Zeolite as Highly Active Catalyst for Removal of Nitrogen Monoxide from Emission of Diesel Engines", Sato et al., Applied Catalysis, vol. 70, L1-15, 1991.
Chattha Mohinder S.
Subramanian Somasundaram
Dees Carl F.
Ford Motor Company
Malleck Joseph W.
May Roger L.
LandOfFree
Catalyst system for treating the exhaust from a lean-burn gasoli does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Catalyst system for treating the exhaust from a lean-burn gasoli, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Catalyst system for treating the exhaust from a lean-burn gasoli will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-325548