In this study, the microstructure and oxidation behaviour of soot from the raw exhaust of a Euro IV test heavy duty (HD) diesel engine are investigated and compared to that of spark-discharge soot and hexabenzocoronene (HBC, C 42H18). We find a microstructure-controlled reactivity towards oxidation of all three samples in 5% O2 in N2. The spark-discharge soot with its fine primary particles and fullerenoid structure has an onset temperature of 423K for combustion, while the HBC with its well-ordered crystallites has a high onset temperature of 773K. Due to an improved combustion process in the Euro IV HD diesel engine, the emitted soot consists of more fullerenoid- or onion-like particles agglomerated in a chain-like secondary structure. The onset temperature of the Euro IV HD engine soot combustion is 573K. Oxidation of the three samples produces only CO 2 and H2O. The different H2O production profiles can be assigned to the functionalised surface of the samples and depend on the soot structure and preparation route.
- Euro IV HD diesel engine soot
- Soot microstructure
- Soot oxidation