Characterization of gasoline soot and comparison to diesel soot: Morphology, chemistry, and wear

Soot from gasoline turbocharged direct injection (GTDI) engines and diesel engines, from exhaust and extracted from oil, were characterized by XRF, XPS, Raman spectroscopy, HRTEM, and Soxhlet extraction followed by GC-MS. Laboratory wear tests with drains and supernatants were also conducted. GTDI soot had less carbon content than diesel soot and can have different PAHs associated with it. GTDI soot extracted from oil either showed the turbostratic structure typical of diesel soot, or appeared sludge-like and decomposed under the TEM beam. The different morphology and chemical composition of GTDI soot from diesel soot can lead to changes in the polarity and hardness of the soot particles and affect the wear mechanism in GTDI and diesel engines.