Mono-, Bi-, and Trimetallic Catalysts for the Synthesis of Multiwalled Carbon Nanotubes Based on Iron Subgroup Metals

Formation features of mono- (Fe, Co, Ni), bi- (Fe-Co, Fe-Ni, Co-Ni), and trimetallic (Fe-Co-Ni) catalysts for the synthesis of multiwalled carbon nanotubes (MWCNTs) prepared by the method of polymerized complex precursors are revealed. It is shown that initial bimetallic and trimetallic catalysts occur in a wide range of phases with spinel structure consisting of different mixed metal oxides (Me(II)Me(III)(2)O-4). The influence of the active component composition and the catalyst activation conditions on their activity in the reaction of MWCNT synthesis is determined. MWCNTs with specific structural characteristics, a narrow diameter distribution and a relatively low degree of defectiveness, can be obtained by varying the composition of the catalyst active component.