Cobalt supported on carbon nanotubes for methane chemical vapor deposition for the production of new carbon nanotubes

Abstract

Carbon nanotube (CNT) application in heterogeneous catalysis has been attracting growing attention. However, the use of CNT-supported catalysts in chemical vapor deposition for the production of new CNT is less addressed in the literature and the characteristics of the produced CNT are usually different from the support. Herein, carbon nanotubes with similar properties to the support were synthesized by methane catalytic decomposition over Co/CNT catalysts at 600 °C. The effects of cobalt loading (10 and 20 wt%) and the catalyst preparation method (incipient wetness impregnation and wet impregnation) were investigated. While the former directly influenced the particle size, the latter influenced the position of cobalt particles. Consequently, both influenced the carbon yield and the properties of the formed CNT. High support surface area and low particle size played key roles in carbon yield. The catalyst prepared by incipient wetness impregnation with 10 wt% of Co loading presented the highest CNT yield (464%) and lowest I_D/I_G (0.82).