CATALYST FOR PURIFYING EXHAUST GAS

摘要

PROBLEM TO BE SOLVED: To improve hydrocarbon(HC) purifying performance by most suitably arranging an HC adsorbent. SOLUTION: A coating layer 2 mainly comprises alumina and a zeolite, on which a noble metal is carried. The composition ratio of alumina to the zeolite in the coating layer is 5:1 to 1:1 in weight ratio. Zeolite adsorbs HC at low temperatures, and the HC discharged from zeolite is oxidized and purified by the noble metal.