Influence of Catalysts on the Preparation of Carbon Nanotubes for Toluene Oxidation

This study aims to investigate the effect of catalysts on the preparation of carbon nanotubes (CNTs) and the catalytic properties of Co/CNT for toluene oxidation between 175 and 250 degrees C. A different ratio of Co to Mo supported on Al2O3 was used in the chemical vapor deposition method to synthesize the carbon nanotubes. Moreover, the catalytic activities of Al2O3-supported catalysts for toluene oxidation were also measured, and the results were compared with the catalytic activities of Co/CNT catalysts. To confirm the characterization of CNT and Co/CNT, the composition and morphology of various catalysts were analyzed by using field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), Raman spectra, BET, and X-ray photoelectron spectroscopy (XPS). The results indicated that the catalytic activity of Co/CNT catalysts was higher than that of the Al2O3-supported catalysts. Furthermore, the catalytic activity of Co/CNT prepared by using 2.4% Co-0.6% Mo/Al2O3 for toluene oxidation was 100% at 225 degrees C. The results demonstrated that the removal efficiency of toluene depends on the species of catalysts synthesized on the carbon nanotubes.