Kinetics of Carbon Nanotube Aerogel Synthesis using Floating Catalyst Chemical Vapor Deposition

Kinetics of formation of carbon nanotube aerogel (CNT-a) by floating catalyst chemical vapor deposition (FC-CVD) has been studied for the first time by thermocatalytic decomposition of ethanol using ferrocene and thiophene as the catalyst and promoter, respectively. Effects of temperature (1423-1573 K), catalyst concentration (1.2-6.5 Pa), and partial pressure of ethanol (120-300 kPa) on the rate of formation of CNT-a have been investigated. The activation energy for the formation of CNT-a was calculated to be 38.5 kJ mol(-1). Various kinetic models were used to determine the rate limiting step(s). Irreversible dissociation of adsorbed ethanol followed by decomposition of the adsorbed ethyl group was found to be rate controlling step for the formation of CNT-a. The atomic ratios of Fe/S and Fe/C were found to have profound effects on the type of CNTs present in CNT-a as characterized by the scanning electron microscopy and Raman spectroscopy.

Automated summary

The kinetics of formation of carbon nanotube aerogel (CNT-a) by thermocatalytic decomposition of ethanol using ferrocene and thiophene as catalyst and promoter has been studied. It was found that the irreversible dissociation of adsorbed ethanol followed by the decomposition of adsorbed ethyl group is the rate limiting step for the formation of CNT-a. Additionally, the atomic ratios of Fe/S and Fe/C were found to have profound effects on the type of carbon nanotubes present in CNT-a.