Development of a Global Kinetic Model for a Commercial Lean NOx Trap Automotive Catalyst Based on Laboratory Measurements

We summarize a global kinetic model for a commercial automotive Lean NO x Trap (LNT) catalyst derived from laboratory flow reactor measurements at Oak Ridge National Laboratory (ORNL). The experimental measurements were made according to a modified version of a publicly shared protocol developed for characterizing the dynamic responses of LNT catalysts over a temperature range of 150–550 °C under lean-rich cycling with CO, H 2 , and C 3 H 6 as the reductants. The resulting model includes three NO x storage sites. The present model also includes reactions for oxygen storage, water gas shift, steam reforming, NO x reduction, and N 2 O and NH 3 generation. When implemented in 1D integral reactor simulations of long-period cycling, the model was found to accurately predict the observed outlet concentrations of CO, H 2 , C 3 H 6 , NO, NO 2 , NH 3 , and N 2 O.