Ozone-assisted diesel soot combustion over Mn2O3 catalysts: A tandem work of different reactive phases

Catalytic diesel particulate filtration (CDPF) assisted by ozone is a promising strategy for soot elimination at exhaust temperatures. It is important yet challenging to utilize the strongly oxidizing ozone while prevent its escape. In this study, rod-like Mn2O3 catalysts with high ozone decomposition ability were proved as an ideal tool for such a task. With thorough characterizations and temperature-programmed oxidation tests in selected atmospheres, triple low-temperature incubation effects were ascribed to the (catalytic) decomposition of ozone, including oxidizing NO to NO2, breeding surface oxygen complexes on soot and surface manganese species on the catalyst. Superior soot elimination efficiency (T-10 = 267 degrees C, T-50 = 392 degrees C, TOFMn = 1.0 x 10(-2) s(-1)) was achieved by the tandem work of NO2 (at similar to 200-500 degrees C), NO2-induced nitrates/nitrites (at similar to 200-300 degrees C), surface manganese oxides (at similar to 300-40 0 degrees C) and O-2 (at similar to 400-500 degrees C), indicating the coupling of ozone and transition metal oxides may lead to reliable and cost-effective CDPF systems. (C) 2022 Elsevier Inc. All rights reserved.

Automated summary

This study demonstrates that rod-like Mn2O3 catalysts can serve as an ideal tool for catalytic diesel particulate filtration (CDPF) by decomposing ozone and achieving efficient soot elimination at low temperatures. The coupling of NO2, nitrate/nitrite, surface manganese oxides, and oxygen can lead to reliable and cost-effective CDPF systems.