Role of the binary H2SO4–H2O homogeneous nucleation in the formation of volatile nanoparticles in the vehicular exhaust

摘要: Abstract High concentration of volatile nanoparticles (NPs) formed in vehicular exhaust may lead to adverse health effects, and a clear understanding the nucleation mechanisms these particles remains be achieved. We investigate role H2SO4–H2O binary homogeneous (BHN) formation NPs diluting exhaust, using recently developed kinetic BHN model suitable for studying process rapidly exhaust. For vehicles running on fuel with sulfur content (FSC) ∼330 ppm we found that significantly contribute NP formation, especially when ambient temperature is low relative humidity high. Our simulations show rate very sensitive FSC sulfuric acid conversion efficiency (es). es value 1%, negligible under typical conditions ∼4% even after reduced below ∼50 ppm. The sensitivities via key factors (including humidity, FSC, soot number concentration) are presented.