Evidence for the Presence of Fullerene in Diesel Soot Using Laser Desorption/Ionization Mass Spectrometry

Abstract

Intact soot exhausted from diesel engines from a large cargo ship and from a farm tractor, which work with heavy and light oil respectively, has been analyzed using laser desorption/ionization (LDI) mass spectrometry. Caged carbon clusters (or fullerene family) were detected as molecular ions M ῍ῌ with relatively intense peaks at m/z 600, 720, and 840 corresponding to C50, C60, and C70, respectively. There were also other even number carbon clusters C2n (nῌ20῍142 or higher). Small carbon clusters Cn (nῌ7῍29) with the magic number nῌ7, 11, 15, 19, 23, and 27 were also observed in the LDI mass spectra. The LDI mass spectra of a fullerene C60 (99῍) and intact soot showed definite metastable ion peaks originating from successive C2 loss from molecular ions. It was confirmed that under the same LDI conditions the laser vaporization of graphite never gives any products of the fullerene family or even number carbon clusters.

Synthesis of Single-Wall Carbon Nanotubes from Diesel Soot

“…5) In addition, it seems that the mean diameter of SWNTs synthesized from fullerenes is slightly smaller than that of SWNTs synthesized from normal graphite. 5) According to our recent report, 13) diesel soot contains C 60 , C 70 and other fullerenes. These fullerenes are thought to be formed during the combustion of light or heavy oil.…”