A layered, three-way conversion catalyst having the capability of
simultaneously catalyzing the oxidation of hydrocarbons and carbon
monoxide and the reduction of nitrogen oxides is disclosed. In one or
more embodiments, the catalyst comprises three layers in conjunction with
a carrier: a first layer deposited on the carrier and comprising
palladium deposited on a refractory metal oxide and an oxygen storage
component; a second layer deposited on the first layer and comprising
rhodium deposited on a refractory metal oxide and an oxygen storage
component; and a third layer deposited on the second layer and comprising
palladium deposited on a refractory metal oxide.