초록 ▼

A catalyst for purifying an exhaust gas for simultaneously removing carbon monoxide, hydrocarbons and nitrogen oxides contained in the exhaust gas under an oxygen rich atmosphere, comprising a carrier composed of a porous material, and barium oxide, lanthanum oxide and platinum supported on the carr

A catalyst for purifying an exhaust gas for simultaneously removing carbon monoxide, hydrocarbons and nitrogen oxides contained in the exhaust gas under an oxygen rich atmosphere, comprising a carrier composed of a porous material, and barium oxide, lanthanum oxide and platinum supported on the carrier, and a method for purifying an exhaust gas by bringing the exhaust gas under an oxygen rich atmosphere into contact with the above-mentioned catalyst.

대표청구항 ▼

[ We claim:] [1.] A method for purifying an oxygen rich exhaust gas simultaneously of, its contents of carbon monoxide, hydrocarbons and nitrogen oxides, comprising:bring the oxygen rich exhaust gas discharged from an engine into contact with a catalyst for purifying the exhaust gas consisting essen

[ We claim:] [1.] A method for purifying an oxygen rich exhaust gas simultaneously of, its contents of carbon monoxide, hydrocarbons and nitrogen oxides, comprising:bring the oxygen rich exhaust gas discharged from an engine into contact with a catalyst for purifying the exhaust gas consisting essentially of (i) at least one porous carrier material selected from the group consisting of alumina, zeolite, zirconia, silica and silica-alumina having applied thereto a combination of (ii) barium oxide and lanthanum oxide, at least a portion of each of the two oxide materials forming a composite barium-lanthanum oxide having the formula BaLa.sub.2 O.sub.4, and (iii) platinum particles supported on the Ba,La oxide bearing carrier, the composite barium-lanthanum oxide being present in an amount sufficient to suppress the formation of LaAlO.sub.3 which forms during operational use of the catalyst, which causes deterioration of the catalyst under the oxygen rich conditions of the exhaust gas treatment and to suppress the grain growth of platinum particles, which grain growth adversely affects the catalyst activity.