Description |
The goal of this research was to provide a better understanding of how soot oxidation kinetics are affected by nanostructure, surface functional groups (SFGs) , C-C sp2,C-C sp3, phenol, carbonyl and carboxylic, pressure, and type of fuel. The oxidation kinetics of soot were studied using thermogravimetric analysis (TGA) to determine kinetic parameters such as the kinetic rate of oxidation, activation energy and pre-exponential factor using Arrhenius kinetics. High-resolution transmission electron microscope (HRTEM) was used to obtain images of the soot and an image analysis algorithm identified the fringe length and tortuosity of the soot samples, which are indications of soot nanostructure. A high-pressure TGA was used to partially oxidize samples at a range of pressures, which were then studied using image analysis to identify changes in the nanostructure. The surface functional groups were studied using X-ray photoelectron spectroscopy and CasaXPS, peak-fitting software was used for identification of the SFGs present. The more structured soot had higher activation energies and slower kinetic rates while soot with less structure demonstrated lower activation energies and faster kinetic rates. There was no significant correlation found between SFGs and oxidation behavior. |