Dielectric barrier discharge plasma catalysis for diesel particulate matter oxidation: Optimization and synergistic differences in transition metal catalysts

Nonthermal plasma (NTP) enhanced catalytic oxidation of diesel particulate matter (DPM) is promising for applications. The synergistic effects of transition metal oxides (MO x , M = Mn, Cu, Ce, Fe, Co, Ti) and dielectric barrier discharge (DBD) plasma on DPM oxidation were investigated, and Fe 2 O 3 showed the best synergistic effect. Cobalt-doped iron oxide (Co–FeO x ) displaying a spinel structure showed the best performance among M –FeO x ( M = Co, Ce, Cu, Zn, Mn). The main intermediate product generated during the catalytic oxidation of DPM is monodentate carbonate. Under DBD plasma, a strong oxidizing intermediate ferrate (FeO 4 2− ) mainly produced at 100–200°C can promote the low-temperature oxidation of DPM.