DIESEL OXIDATION CATALYST WITH LAYERED STRUCTURE CONTAINING CERIA COMPOSITION AS PALLADIUM SUPPORT MATERIAL FOR ENHANCED HC AND CO GAS CONVERSION

摘要

A layered diesel oxidation catalyst (DOC) comprises: a) a carrier substrate; b) a diesel oxidation catalytic material comprising bl)a first layer located on the carrier substrate, the first layer comprising palladium impregnated on a support material comprising ceria in an amount of at least 45 weight% based on the total weight of the support material, and optionally comprising platinum; b2) a second layer located on the first layer, the second layer comprising palladium and platinum each impregnated on a support material comprising a metal oxide; wherein the platinum to palladium weight ratio of the first layer is lower than the platinum to palladium weight ratio of the second layer.