Patent attributes
Described is a catalyst comprising a substrate and a catalyst coating of two or more layers: (a) a first layer comprising Pd and Rh on the substrate; and (b) a second layer comprising Pt and/or Pd on the first layer; these layers each further comprising: one or more particulate support materials; one or more oxygen storage component (OSC) materials; and one or more nitrogen oxide storage materials comprising one or more elements selected from the group of alkali and/or alkaline earth metals, wherein the total amount of alkali and alkaline earth metals ranges from 0.18 to 2.0 g/in3 calculated as the respective alkali metal oxides M2O and alkaline earth metal oxides MO. Also described is a method for the production of a catalyst, as well as a process for the treatment of a gas stream, in particular of an exhaust gas stream resulting from an internal combustion engine.
