This project consists in a basic research of the reactivity of Diesel soot deposited on a metallic filter. Main results lie in the scientific field. They consist in the understanding of the reaction mechanism of Diesel soot with exhaust gases, in particular nitrogen dioxide and oxygen. The promoting effect of water vapour is also considered. The effect of the presence of an oxidizing catalyst is also studied in terms of reaction mechanism and in terms of kinetics of soot combustion.
A detailed kinetic model, which encompasses the effect of these exhaust gas components, has been set-up and could be validated for real Diesel soot deposit on metallic filter.
The developed kinetical model applies for thin layer of Diesel soot deposited on a metallic filter.
The outputs of this project may be used for prediction and validation of the regeneration strategy of soot traps. In particular, the effect of catalytically active coating of the filter may be assessed for a higher efficiency of the CRT process. The kinetical data provided by this study are required for a complete modelisation of the soot trap regeneration.
The effect of a Pt-based catalyst on the soot oxidation rate was also investigated in the temperature 300-400°C. A substantial increase of the oxidation rate is obtained for Pt supported on ferrierite. Also, Ru-based catalysts were investigated. They are looking quite promising as a substitute for Pt. Moreover, the activity of Ru catalysts in the NO2-O2-NO system for carbon oxidation shows some interesting features, which would need further investigation.