CATALYTIC GROWTH OF HIGHLY ORDERED CARBON NANOFIBERS FROM NICKEL/SILICA: ROLE OF POTASSIUM AND BROMINE AS PROMOTERS

摘要

In a recent communication (J. Phys. Chem. B, 2000, 104, 4281-4284) the author reported the unexpected catalytic growth of highly ordered carbon filaments during the hydrodechlorination of chlorobenzene over Ni/SiO_2 at the remarkably low temperature of 553 K. This low temperature growth can be attributed to the presence of Br and K on the catalyst surface that facilitated a restructuring of the active Ni sites leading to a destructive chemisorption of the reactant that preceded the dissolution and precipitation of carbon in an ordered fashion. The work reported herein sets out to build on this serendipitous carbon growth, focusing on ethylene decomposition as a route to filamentous carbon and considering the effects of incorporating of Br and K into a selected parent Ni/SiO_2 samples on the carbon yield and structure.