Quantum Chemistry Calculations of NOx Species on a NOx Trap Surface

William  Pitz, Lawrence Livermore National Laboratory

Quantum Chemistry Calculations of NOx Species on a NOx Trap Surface

Christopher J. Mundy, I-feng W. Kuo and William J. Pitz
Lawrence Livermore National Laboratory

Thermal/fluid codes are being developed to model NOx trap aftertreatment devices.  These codes require surface chemistry submodels to treat the adsorption and desorption of NOx species on the trap surface.  To develop surface chemistry submodels, the controlling surface species and reactions must be identified.  Ab initio molecular dynamics techniques allow the identification of important surface moieties that control the surface reactions.  In this work, Car-Parrinello molecular dynamics is used to model important surface moieties on the NOx trap surface.  For the first time, a much more realistic barium carbonate surface is modeled.  In previous studies in the literature, only barium oxide surfaces have been attempted.