Title: Catalytic Chemical Vapor Deposition Synthesis of Carbon Nanotubes from Methane on SiO Supported Fe and Fe−Ni Catalysts

Influences of operating conditions on the production of carbon nanotubes (CNTs) were studied using Fe and Fe-Ni bimetallic catalysts supported on silicon monoxide (SiO). The catalysts were prepared in three steps: (1) impregnation of SiO powders with ferric nitride or combinations of ferric and nickel nitrides, (2) oxidation of nitrides in an air stream, and (3) grinding the powders obtained. CNTs were successfully synthesized by catalytic CVD using NH3/CH4 mixtures in a horizontal tubular flow reactor. The following process parameters were varied to investigate their effects on the growth rates of CNTs. The morphologies of catalysts and product CNTs were observed by scanning electron microscope (SEM). • The particle size of SiO, • metal composition, • metal loading, • temperature for catalyst oxidation, • extent of grinding of catalysts, • NH3 pretreatment time