Patent ID: 6272848
Filing Date: 2001-08-14
Classification: B01D,F01N,F02D

Abstract:
An exhaust gas purifying apparatus for an internal combustion engine, having a SOx absorbent and a NOx purifying catalyst each arranged in an exhaust path of the internal combustion engine in which lean burn is effected, said SOx absorbent absorbing SOx in an inflow exhaust gas under an oxidizing atmosphere in which the O.sub.2 concentration of said exhaust gas is higher than a stoichiometric ratio required for completely burning a reductive component contained in said exhaust gas, and releasing the absorbed SOx under a reducing atmosphere in which the O.sub.s concentration of an exhaust gas is lower than a stoichiometric ratio required for completely burning a reductive component contained in said exhaust gas, said NOx purifying catalyst capturing NOx in said exhaust gas under the oxidizing atmosphere in which the O.sub.2 concentration of said exhaust gas is higher than a stoichiometric ratio required for completely burning a purifying component contained in said exhaust gas,wherein as said NOx purifying catalyst, there is provided a NOx chemisorption reduction catalyst chemically capturing NOx as NO.sub.2 on a surface of said NOx purifying catalyst under said oxidizing atmosphere and reducing the chemically captured NO.sub.2 with said reductive component to N.sub.2 to release the N.sub.2 from the surface of said NOx purifying catalyst under said reducing atmosphere.