Unique Properties of Gasoline Direct Injection (GDI) Engine Particulate Matter (PM)
Heeje Seong, Argonne National Laboratory
Title: Unique Properties of Gasoline Direct Injection (GDI) Engine Particulate Matter (PM): Examinations of PM Morphology, Nanostructures, and Oxidative Reactivity
Recent studies showed that GDI engines increase PM emissions in mass and number to a noticeable level, compared to conventional gasoline engines â€“ port-fuel-injection (PFI) spark-ignition engines. To successfully meet the stringent PM standards, therefore, particulate filter systems such as gasoline particulate filter (GPF) have been developed. For better understanding of GDI engine PM, particulate properties were investigated in terms of primary & aggregate size distributions, nanostructures and surface functional groups using HRTEM, Raman spectroscopy and FTIR-ATR. Our studies revealed unique properties of GDI PM, distinct from diesel PM: there found a number of solid carbon nanoparticles in the sub-23-nm range. Also, GDI particles were often observed to undergo particle growth by exposing to a high-energy electron beam during HRTEM measurements. In the presentation, PM oxidative reactivity will also be discussed related to physicochemical properties of GDI PM, such as ash content, surface functional groups and carbon crystalline structure.