Study on the effect of Ce1-xMnxO2 catalyst on improving diesel emission performance

Abstract

To reduce diesel emissions while permitting the passive regeneration of the diesel particulate filter (DPF) at low temperatures, we developed three after-treatment DPF devices. These devices consisted of a ceramic body that was either bare or loaded with the catalysts CeO2 (DPF-CeO2) or Ce0.5Mn0.5O2 (DPF-Ce0.5Mn0.5O2). The effects of these units on soot, NOx, CO, and hydrocarbon emissions were assessed. On average, the DPF-Ce0.5Mn0.5O2 device outperformed the DPF-CeO2 device. In addition, increasing the engine load was found to raise the exhaust temperature while increasing the soot oxidation efficiency and reducing soot emissions. The maximum soot removal percentages of the DPF-CeO2 and DPF-Ce0.5Mn0.5O2 were 37.6% and 55.1%, respectively, under B100 working conditions. The extent of NOx removal also gradually increased as the load increased, and the average removal percentages were 8.6% and 15.0%, respectively. Both catalytic devices lowered CO emissions to a much greater extent than the bare DPF, with average removals of 45.8% and 55.6%, respectively, while the average hydrocarbon oxidation values were 39.1% and 50.9%, respectively. Notably, the hydrocarbon emissions were almost zero after Ce1-xMnxO2 catalysis under C100 working conditions.