Patent ID: 6559086
Filing Date: 2003-05-06
Classification: B01D,B01J,F01N,Y02T

Abstract:
A catalyst for purifying an exhaust gas, wherein the catalyst reducing and purifying nitrogen oxides in an oxygen rich atmosphere which contains oxygen more than necessary for oxidizing components to be oxidized in the exhaust gas by hydrocarbon (HC) adsorbed on a zeolite support, and wherein:said zeolite support comprises a first zeolite loaded with at least a catalyst metal selected from the group consisting of Pt, Rh, Pd, Ir and Ag, and at least an alkali component selected from the group consisting of alkali metals and alkaline-earth metals, and a second zeolite free from loading a catalyst metal and an alkali component, wherein both the first zeolite and the second zeolite are mixed in a powdered state, and said first zeolite is Â¼-Â½ by weight ratio of all zeolites.