Investigation of Transition Metal Oxide Catalysts for Diesel PM Removal Under Plasma Discharge Conditions

摘要

Seven different transition metal oxides (TiO2, ZnO, V2O5, Fe2O3, Co3O4, MnO2, and CuO) have been investigatedfor oxidation of diesel particulate matter (PM) under plasma discharge conditions. The experiments were carried outby measuring PM oxidation rates over each catalyst using a batch-type dielectric barrier discharge reactor. It was foundthat TiO2, ZnO, V2O5, and Fe2O3 can promote PM oxidation, among which Fe2O3 is a most desirable catalyst for PM oxidativeremoval as PM oxidation rate promoted by Fe2O3 is highest under plasma discharge conditions. The mechanism ofPM catalytic oxidation over the metal oxides has been suggested to follow the redox catalytic cycles from the correlationof the catalytic oxidation rates with the formation enthalpies per oxygen atom of the catalysts. O atoms generated byplasma discharges may play an important role in promoting the re-oxidation of the catalysts. The highest catalytic activityfor the PM oxidation with Fe2O3 has been suggested to be due to the balance between the reduction rate and the reoxidationrate within the redox catalytic cycles.