EXHAUST PURIFICATION CATALYST

摘要

An exhaust purification catalyst (1) has a substrate (2), a lower layer (3) for covering the substrate (2) and containing an oxygen storage material and palladium but not containing rhodium, and an upper layer (4) for covering the lower layer (3), containing rhodium and a carrier that carries the rhodium, and having lower oxygen storage ability than the lower layer (3). The construction enables the catalyst to achieve high exhaust purification efficiency both in a state immediately after an engine is started and in a state where the engine has been continuously operated, and the construction also enables the catalyst to be of low cost.