| abstract |
A catalyst (20) being formed of a porous supporter supportingnalkali metals, Ti and noble metal, or further supportingnat least one of rare earth metal and magnesium, beingndisposed in a flow passage of the internal combustion enginen(7), and being used to purify NO x contained in the exhaustngas. The above catalyst (20) has excellent NO x resistancennot only to the exhaust gas burnt with the stoichiometricnair-to-fuel ratio or rich condition, but to thenexhaust gas burnt with the lean condition, and furthermorenhas a high resistivity to poisoning of SO x slightly containednin the fuel. |