Progress in the development of NOx adsorber catalysts for DI gasoline engines

In this article by Engelhard Technologies, recent progress in NOx trap emission control for lean-burn gasoline engines is described on the basis of defined performance criteria. The influence of different ageing conditions on the maximum temperature stability of NOx adsorbers is presented. The maximum temperature stability and the operating temperature range of current NOx adsorbers require the use of a close-coupled pre-catalyst. For series application, the maximum temperature load of the adsorbers must be limited in order to guarantee durability.