Exhaust gas purification catalyst device

Abstract

An exhaust gas purification catalyst device having a honeycomb substrate that has a plurality of exhaust gas flow paths divided by a partition wall, a catalyst noble metal particle carrier layer provided in or on the partition wall of the substrate, and a zeolite layer containing a copper ion exchange zeolite, the zeolite layer being located closer to the exhaust gas flow paths than the catalyst noble metal particle carrier layer, wherein the catalyst noble metal particle carrier layer includes catalyst noble metal particles, and the exhaust gas purification catalyst device furthermore has an inorganic oxide particle layer located between the catalyst noble metal particle carrier layer and the zeolite layer, the inorganic oxide particle layer containing non-silica inorganic oxide particles and having a catalyst noble metal content of less than 0.01 g/L.

Dependencies are inferred from the claim text.