Fluidized-bed production of 0.3 mm-long single-wall carbon nanotubes at 28% carbon yield with 0.1 mass% catalyst impurities using ethylene and carbon dioxide

Abstract

To produce carbon nanotubes (CNTs) practically, a high carbon source concentration and high carbon yield are essential. By feeding moderately active ethylene at 10–20 vol% with mildly oxidative carbon dioxide at 1 vol%, submillimeter-long single-wall CNT (SWCNT) arrays were synthesized via fluidized-bed chemical vapor deposition using an Fe/AlOx catalyst sputtered on ceramic beads. SWCNTs with an average diameter of 2.9 nm, long length (0.3 mm), low catalyst impurity (0.1 mass%), and high specific surface area (1178 m2/g) were obtained at a high carbon yield of 28%. This study thus introduces a route for more efficient and cleaner production of long and pure SWCNTs.