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NOxstorage catalysts (NSCs) are utilizedto reduce the emissions in lean-burning engines such as diesel andlean-burn Otto engines. One of the current limitations of this technologyis catalyst aging due to high-temperature excursions. To guaranteehigh conversions and to adapt engine and catalyst management, simulationsof the exhaust line require a proper description of the conversionbehavior of aged NSCs. Because of their complex chemical constitution(three precious metals, two storage components), kinetic models ofNSCs encompass a large number of model parameters, which are determinedfrom extensive experimental investigations. In this contribution,we show that the kinetics of aged NSCs can be derived from the kineticsof the fresh catalyst plus a relatively small set of experiments neededto quantify catalyst degradation. Seven scaling factors are necessary,which can be regressed one by one from simple test experiments. Thescaling factors account for precious-metal sintering, reduced bariumand oxygen storage capacities, reduced NO oxidation rate, and retardedwater–gas shift reaction. All oxidation reactions require onescaling parameter, and the same is true for the reduction reactions.In addition, one parameter is required that accounts for the deceleratedkinetics during the regeneration of barium nitrate. [ABSTRACT FROM AUTHOR]