Mechanism of Diesel PM Removal in Plasma Discharges

摘要

The mechanism of particulate matter (PM) oxidization by plasma discharges is investigated using thermogravimetry (TG) and x-ray photoelectron spectroscopy (XPS). O2, H2O and NO in diesel exhaust gases can be activated to O, OH, O3, and NO2 by plasma discharges. PM is expected to react with these active oxygen species to yield CO and CO2. The results of XPS analysis showed that the ratio of sp 2 bonding decreased and the ratio of sp 3 bonding increased by plasma treatment, while the ratio of sp 2 bonding increased, and the ratio of sp 3 bonding decreased by O3 treatment. It is suggested that PM is removed by the combination of the reactions of plasma discharge and active oxygen species.