US Patent 10018095 Exhaust gas purification device

The exhaust gas purification device according to the present invention includes a substrate of wall flow structure having a porous partition wall 16, and a catalyst layer held in internal pores of the partition wall 16. The catalyst layer contains, as a carrier, an OSC material having oxygen storage capacity. In the thickness direction of the partition wall 16, the porosity of the internal pores in inlet regions 16a is 25% or higher, and an average occupation ratio of the catalyst layer held in the internal pores is 75% or lower.