| abstract |
An ammonia oxidation catalyst device 10, comprising a substrate 3, a first catalyst coat layer 1 and a second catalyst coat layer 2, wherein: the first catalyst coat layer 1 includes inorganic oxide particles MO and a catalytic noble metal PGM supported on the inorganic oxide particles MO; the second catalyst coat layer 2 includes an NO x selective reduction catalyst SCR and a proton zeolite H-Zeolite; the first catalyst coat layer 1 is present on the substrate 3; and the second catalyst coat layer 2 is present on the first catalyst coat layer 1. |