Formation of Carbon Nanofibers and Carbon Nanotubes through Methane Decomposition over Supported Cobalt Catalysts

• DOI: 10.1021/jp048827t
• Publication Date: 2004-07-29T05:03:50Z
• Authors: Sakae Takenaka; Minoru Ishida; Michio Serizawa; Eishi Tanabe; Kiyoshi Otsuka
• Keywords: Carbon fibers

Catalytic performance of Co catalysts supported on different supports (MgO, Al2O3, SiO2, and TiO2) for the formation carbon nanofibers through methane decomposition was investigated. activity life at 773 K strongly depended type catalytic supports; i.e., performances Co/Al2O3 Co/MgO were superior to those Co/TiO2 Co/SiO2. All produced with relatively uniform diameters (10−30 nm) reaction irrespective kind supports, although an average crystallite size metal these catalysts. These results implied that particles from 10 30 nm grew preferentially, while ones larger than inactive reaction. The structures carbons formed by over temperatures. Multiwalled nanotubes (MWCNT) mainly in temperature range 873−973 K, where catalytically active present tip or hollow MWCNT. On other hand, helically coiled bamboolike preferentially 1073 could be rarely observed carbons. growth mechanisms changed according K-edge XANES EXAFS suggested species always as during decomposition, kinds