Comparison of single-wall carbon nanotubes prepared by catalytic decomposition of methane and disproportionation of carbon monoxide over different catalysts

Abstract

Single-wall carbon nanotubes (SWNT) exhibit outstanding mechanical and electrical properties, which can be utilized for various potential applications. Currently, the catalytic decomposition of carbon-containing gases is the most promising pathway for the large-scale production of SWNT. Consequently, in order to produce high quantity of SWNT, carbon-containing gases, catalyst formulations, as synthesis conditions have been studied. In this work, methane, carbon monoxide, and their mixtures were systematically tested over a series of Ni-Mo, Co-Mo, and Fe-Mo catalysts supported on silica gel, magnesium oxide and alumina. Raman spectroscopy, temperature programmed oxidation and transmission electro microscopy were used to characterize the deposited carbon on the catalysts. The results showed that CO yielded high quality of SWNT on all supports except on MgO, while methane gave high amounts of deposited carbon but low selectivity towards SWNT. Characterization results also suggested that CO and CH3 react independently when used in combination.