Considerations on the key precursor for the growth of carbon nanotubes using a diesel engine as a reactor.

Carbon nanotube (CNT) was synthesized during combustion in a diesel engine by adding catalyst sources into fuel. Fuel used in this study was a mixture of normal dodecane/ethanol, methyl laurate/ethanol, and 1-decanol/ethanol. The analysis of an exhaust gas using a gas chromatograph revealed that the amount of carbon monoxide was most influential on the CNT formation than other factors such as adiabatic combustion temperatures and/or the amount of low molecular weight hydrocarbons like acetylene and ethylene. The significance of carbon monoxide in our system was also suggested by simulated and modeling works. Simulations of combustion reactions inside a cylinder were performed through CHEMKIN-PRO software for a qualitative evaluation. Modeling works of CNT growth rates were carried out by means of not only CO related reactions but also ethylene and acetylene related reactions as a source of carbon deposition. It was suggested that carbon monoxide had stronger connection with CNT synthesis in a diesel engine compared with other potential CNT precursors such as ethylene and acetylene. Furthermore, we proposed CNT growth route in our system by considering characteristics of combustion in a diesel engine. [ABSTRACT FROM AUTHOR]