Influence of catalysts' activation on their activity and selectivity in carbon nanotubes synthesis

In this paper we have investigated the influence of catalysts' activation conditions on their selectivity in carbon nanotubes CVD synthesis by means of methane decomposition reaction using Fe- and FeCo-catalysts synthesized via polymerized complex rout providing homogeneous distribution of catalytic components. It was shown that variation of catalysts' reduction conditions results in formation of different types of NTs (MWNTs or SWNTs). The most effective catalyst activation leading to formation of SWNTs consists in catalyst reduction by reaction mixture at high temperature. That can be explained in terms of carbon deposits nucleation on metals. (c) 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.