Carbon oxidation generated in diesel engines using iron-doped fuel

The soot oxidation activity of metallic iron nanoparticles was studied under real diesel engine conditions. Particulate matter (PM) was sampled at distinct temperatures, using fuels containing ferrocene. The results indicated an 80% reduction of accumulated PM using fuels doped with 50 ppm ferrocene at a temperature of 460 ◦C. Temperature-programmed catalytic oxidation tests indicated that PM oxidation in ferrocene-doped fuels starts at an approximately 200 ◦C lower temperature. The transmission electron microscopy (TEM) analysis of the PM revealed that soot agglomerates with and without the presence of Fe showed a similar morphology and that the average diameter of iron nanoparticles is 10 nm. The use of ferrocene-doped diesel fuels increases the speed of PM oxidation significantly, enabling the filter to self-regenerate at the average temperature of the exhaust gases. Moreover, 500 ppm of sulfur in fuels does not reduce the catalytic activity of iron nanoparticles in PM oxidation.