Exhaust gas purification catalyst

An exhaust gas purification catalyst in which a catalytic coating containing plural kinds of catalytic precious metals other than platinum, at least one kind of particulate alumina and at least one kind of particulate oxygen storage component is coated on a honeycomb support, wherein

• the catalytic coating is formed of an upper layer and a lower layer,
• each of particles of the at least one kind of particulate alumina and the at least one kind of particulate oxygen storage component carries only one of the plural kinds of catalytic precious metals,
• the plural kinds of catalytic precious metals include palladium and rhodium,
• said palladium is carried on particles of the particulate alumina and particles of the particulate oxygen storage component both of which are disposed in the lower layer,
• said rhodium is carried on particles of the particulate alumina and particles of the particulate oxygen storage component both of which are disposed in the upper layer, and
• the mass ratio Pd/Rh between said palladium and said rhodium is in the range from 4/1 to 7/1 both inclusive.

An exhaust gas purification catalyst in which a catalytic coating containing at least one kind of catalytic precious metal, at least one kind of particulate alumina and at least one kind of particulate oxygen storage component is coated on a honeycomb support, wherein

• the catalytic coating contains rhodium as the at least one kind of catalytic precious metal,
• said rhodium is carried on one said kind of particulate alumina and one said kind of particulate oxygen storage component,
• the rhodium-carried particulate alumina has a larger specific surface area than the rhodium-carried particulate oxygen storage component, and
• the one kind of particulate oxygen storage component carries a larger amount of rhodium per unit specific surface area than the one kind of particulate alumina.

An exhaust gas purification catalyst in which a catalytic coating containing a particulate oxygen storage component is coated on a honeycomb support, said particulate oxygen storage component containing cerium, zirconium and one or more rare earth elements other than cerium, wherein

• the particulate oxygen storage component comprise different kinds of particulate oxygen storage components having different mass ratios, each of the mass ratios being expressed by ZrO2/(CeO2+ZrO2+one or more rare earth element oxides),
• the catalytic coating is formed of an upper layer and a lower layer,
• the lower layer contains said particulate oxygen storage component of the kind having a mass ratio of 70 mass % or less, and
• the upper layer contains said particulate oxygen storage component of the kind having a mass ratio of more than 70 mass %.