Diesel Engine Exhaust Emission:Oxidative Behavior and Microstructure of Black Smoke Soot Particulate

摘要

Soot particulate collected from a Euro III heavy duty diesel engine run under black smoke conditions was investigated using thermogravimetry,transmission electron microscopy,electron energy loss spectroscopy,and X-ray photoelectron spectroscopy.The characterization results are compared with those of commercial carbon black.The onset temperature toward oxidation of the diesel engine soot in 5% O_2 is 150 deg C lower than that for carbon black.The burn out temperature for the diesel engine soot is 60 deg C lower than that of the carbon black.The soot primary particles exhibit a core-shell structure.The shell of the soot particles consists of homogeneously stacked basic structure units.The commercial carbon lamp black is more graphitized than the diesel engine soot,whereas the diesel engine soot contains more carbon in aromatic nature than the carbon black and is highly surface-functionalized.Our findings reveal that technical carbon black is not a suitable model for the chemistry of the diesel engine soot.