In this paper a global reaction kinetic model is used to understand and describe the NOx storage/reduction process in the presence of CO2 and H2O. Experiments have been performed in a packed bed reactor with a Pt-Ba/gamma-Al2O3 powder catalyst (1 wt% Pt and 30 wt% Ba) with different lean/rich cycle timings at different temperatures (200, 250, and 300 degrees C) and using different reductants (H-2, CO, and C2H4). Model simulations and expefimental results are compared. H2O inhibits the NO oxidation capability of the catalyst and no NO2 formation is observed. The rate of NO storage increases with temperature. The reduction of stored NO with H-2 is complete for all investigated temperatures. At temperatures above 250 degrees C, the water gas shift (WGS) reaction takes place and H-2 acts as reductant instead of CO. At 200 degrees C, CO and C2H4 are not able to completely regenerate the catalyst. At the higher temperatures, C2H4 is capable of reducing all the stored NO, although C2H4 poisons the Pt sites by carbon decomposition at 250 degrees C. The model adequately describes the NO breakthrough profile during 100 main lean exposure as well as the subsequent release and reduction of the stored NO. Further, the model is capable of simulating transient reactor experiments with 240s lean and 60s rich cycle timings. (C) 2008 Elsevier Ltd. All rights reserved.