Parametric Study of Carbon Nanofiber Growth by Catalytic Ethylene Decomposition on Hydrotalcite Catalysts Zhixin Yu1, De Chen1, Bård Tøtdal2, and Anders Holmen1 1 Department of Chemical Engineering, 2 Department of Physics, Norwegian University of Science and Technology, N-7491, Trondheim, Norway Abstract Novel catalysts are presented to synthesize carbon naofiber (CNF) from ethylene decomposition. The catalysts are derived from hydrotalcite (HT) precursors which contain high amount of active species. The synthesis process has been studied and optimized as a function of various parameters such as hydrogen content, gas space velocity, temperature, and catalyst composition. The influence of these parameters on the deposited carbon nanostructure and quality is investigated. The behaviour of the CNF yield and quality with respect to these parameters enlightens the ways to improve the process. The aim of the present article is to report the optimized large scale (hundred grams per gram catalyst) production process of high quality CNFs at relatively low temperatures (<650 C). The process is fully reproducible and can be easily scaled up. Some results: 10 nm 10 nm Fig.1. HR-TEM images show the fishbone structure CNFs produced at 600 C on the 6:1 catalyst (a) C2H4/CO/H2 (30:10:10); (b) C2H4/CO/H2 (30:10:15). The inclination angle is marked.