Emission treatment catalysts, systems and methods

A system for treating an exhaust stream comprising NOx from an engine, the system comprising:

• a diesel oxidation catalyst comprising an inlet zone with an axial length and an outlet zone with an axial length, the inlet zone comprising platinum and palladium in a ratio of equal to or greater than 2:1 in a first loading of at least 75 g/ft3, the outlet zone comprising palladium and no platinum in a second loading of no greater than 10 g/ft3, and the axial length of the inlet zone being less than or equal to the axial length of the outlet zone, wherein the diesel oxidation catalyst is configured such that no more than 25 ppm increase in the NO2 produced over about 90% of the operating window of the diesel oxidation catalyst, and wherein the inlet zone or the outlet zone comprises a base metal that is an oxide of a rare earth metal;
• a catalyzed soot filter disposed downstream from the diesel oxidation catalyst, the catalyzed soot filter comprising an oxidation catalyst composition on the filter, wherein the oxidation catalyst composition with platinum group metals loading on the filter is configured to produce NO2 to optimize a ratio of NO to NO2 exiting the filter;
• and
• a NOx reducing catalyst located downstream from the catalyzed soot filter.