Supported catalysts derived from cobalt phyllosilicates for chemical vapor deposition growth of single-walled carbon nanotubes

Abstract

Chemical vapor deposition (CVD) growth of single-walled carbon nanotubes (SWNTs) using supported catalyst is problematic due to possible metal coalescence during reaction. Thus, the development of supported catalyst that resists sintering is crucial for synthesizing SWNTs with a narrowly distributed chirality. Here, silica-supported phyllosilicate materials containing Co are prepared for catalytically growing carbon nanotubes. Owing to the incorporation of Co in the phyllosilicate, only part of Co2+ is reduced under CVD reaction environment, leading to the formation of immobilized metallic particles which subsequently catalyze the growth of SWNTs at 850 °C. With the addition of Pd promoter, the reducibility and carburization of the Co particles is enhanced, leading to the preferential synthesis of (6, 5) SWNTs at 600 °C. This work extends the application of phyllosilicates in catalytic synthesis of SWNTs, thus providing a new avenue for chirality-selective synthesis of SWNTs.