Diesel oxidation catalyst composite with layer structure for carbon monoxide and hydrocarbon conversion

A layered diesel oxidation catalyst composite for the treatment of exhaust gas emissions from a diesel engine comprising:

• a diesel oxidation catalytic material a carrier, the catalytic material comprising a palladium component, and at least two layers:
• a hydrocarbon trap layer comprising at least one molecular sieve, the hydrocarbon trap layer being substantially free of palladium;
• a palladium-containing layer that comprises the palladium component, and is substantially free of a molecular sieve and is substantially free of an oxygen storage component, wherein the palladium component is located on a high surface area, refractory metal oxide support;
• wherein the catalytic material optionally further comprises an undercoat layer located on the carrier and below the at least two layers;
• and
• wherein the catalytic material further comprises an oxygen storage component that is located in at least one of the hydrocarbon trap and the optional undercoat layers.