Nanostructure effects upon soot oxidation

A dependence of the soot particle nanostructure upon synthesis conditions, i.e., temperature, time, and initial fuel identity, was studied. A corresponding variation in the overall reactivity, reflecting an average of the different reactivities associated with these specific atomic sites arises. This variation was presented between a disordered soot derived from benzene and a graphitic soot derived from acetylene. Their oxidation rates differed by nearly 5-fold. Curvature of layer planes, as observed for an ethanol derived soot, substantially increased oxidative reactivity. The reactivity of a soot particle towards oxidation depended upon its nanostructure, i.e. the size, orientation, and organization of the graphene layer planes. Variations in the graphene layer plane dimensions, curvature, and relative orientation would greatly impact the reactivity of the individual graphene segments, and hence the overall particle reactivity. The results illustrated a dependence of the burnout rate upon the soot nanostructure as governed by both the initial fuel and soot growth conditions.