Three-layered catalyst system for purifying exhaust gases of internal combustion engines

摘要

Disclosed herein is a three-layered catalyst system in which layers including predetermined precious metal components are sequentially layered on a substrate, and thus the conversion ratio of HC and CO is increased, thereby improving purification efficiency. The three-layered catalyst system includes a substrate, a lower layer containing a precious metal component of only platinum, an intermediate layer containing a precious metal component of only palladium, and an upper layer containing a precious metal component of only platinum, all of which are sequentially layered.