Multi-Scale Modeling Study of Barium Nitrate Reduction in NOx Traps

作者：Rankovic Nikola; Nicolle Andre^*; Berthout David; Da Costa Patrick

来源：Topics in Catalysis, 2013, 56(1-8): 140-144.

DOI：10.1007/s11244-013-9943-2

• NOx trap
• Regeneration
• Barium nitrate
• Kinetic modeling
• DFT
• Multi-scale

Nitrogen oxide (NOx) abatement from lean-burning engines is a major environmental challenge for the upcoming years. With increasing regulations in terms of NOx emission, only sophisticated engine aftertreatment techniques can meet the required emissions. Lean NOx Traps (LNT) are one of those few catalytic techniques that are potential candidates for a large-scale application. Their operation is based on alternating NOx storage cycles over a basic storage material with nitrate reducing cycles with an external reductant (CO, H-2 and hydrocarbons). Because of the complex chemistry involved, modeling reactions taking place during storage-reduction cycling is still poorly understood. We address one of the key issues in kinetic modeling related to LNT regeneration that is the competition between direct and indirect reduction pathways. Recent experimental work has evidenced the formation of barium isocyanates but no relevant kinetic modeling has been done up to now. The present modelling study, based on multi-scale approaches (from DFT to kinetic modelling), shows that both direct (isocyanate) and indirect (decomposition) pathways may contribute significantly to nitrate reduction.

• 出版日期2013-5