Boreskov Institute of Catalysis of the Siberian Branch of Russian ...

OP-I-22al., 2008; Monolith, 2008). The NO x storage/reduction experiments are performed in thetemperature range 100-500 °C in the presence of CO 2 and H 2 O.ModellingSpatially distributed NSRC model is developed (Kočí et al., 2008), considering thefollowing ammonia reaction pathway: NH 3 is formed by the reaction of H 2 with NO x and itcan further react with oxygen and NO x deposited on the catalyst surface, producing N 2 .Considering this scheme with ammonia as an active intermediate of the NO x reduction, agood agreement with experiments is obtained in terms of the NO x reduction dynamics andselectivity. Reduction front travelling in the flow direction along the reactor is predicted, withthe NH 3 maximum on the moving boundary. When the front reaches the reactor outlet, themain NH 3 peak is observed in the exhaust gas (Kočí et al., 2008).Under certain operating conditions, a smaller NH 3 peak is observed experimentally at thereactor outlet just after the beginning of the regeneration phase (before the main NH 3 peak).We show that this more complex, double NH 3 peak dynamics can be described by the samespatially distributed model with proper values of kinetic parameters governing the rate of NH 3formation and decomposition.References1. Cumaranatunge L., Mulla S.S., Yezerets A., Currier N.W., Delgass W.N., Ribeiro F.H., Ammonia is ahydrogen carrier in the regeneration of Pt/BaO/Al 2 O 3 NO x traps with H 2 , Journal of Catalysis 246 (2007) 29.2. DieselNet, http://www.dieselnet.com (2008).3. Epling W.S., Campbell L.E., Yezerets A., Currier N.W., Parks J.E., Overview of the Fundamental Reactionsand Degradation Mechanisms of NO x Storage/Reduction Catalysts, Catalysis Reviews 46 (2004) 163.4. Epling W.S., Yezerets A., Currier N.W., The effects of regeneration conditions on NO x and NH 3 releasefrom NO x storage/reduction catalysts, Applied Catalysis B: Environmental 74 (2007) 117.5. Kobayashi T., Yamada T., Kayano K. Study of NO x Trap Reaction By Thermodynamic Calculation, SAETechnical Paper 970745 (1997).6. Kočí P., Plát F., Štěpánek J., Kubíček M., Marek M. Dynamics and selectivity of NO x reduction in NO xstorage catalytic monolith, Catalysis Today (2008) in press, doi:10.1016/j.cattod.2007.11.023.7. Monolith, http://www.vscht.cz/monolith (2008).68