CONTROLLED GROWTH AND METROLOGY OF CARBON NANOTUBES ON SUPPORTED Co-Mo CATALYSTS

Abstract

Studies related to selectivity assessment and yield upgrade of different types of Carbon Nanotubes have been conducted in order to determine the optimum supported Co-Mo catalysts design to achieve the desired performance.

Our group has developed and optimized a catalyst highly selective to the production of high (n,m) selectivity Single-Walled Carbon Nanotubes known as CoMoCAT®. In order to make their production more cost effective, different studies were devoted to increasing the carbon yield while keeping the selectivity high (as defined in Appendix A-1). In order to increase the carbon yield, several catalyst formulations have been tried. Catalysts synthesized using the sol-gel method have shown an improvement on the carbon yield while keeping the SWCNT selectivity high. In this work the synthesis of catalysts by using the sol-gel method is shown.

Carbon Nanotubes are widely recognized for being suitable for different applications because of their outstanding properties. Different types of Carbon Nanotubes are desired for different applications. Therefore the synthesis of controlled structure tubes is of high economic interest. Nowadays, the production of controlled structure Multi-Walled Carbon Nanotubes is also desirable not only because they are preferred for some applications over Single-Walled Carbon Nanotubes, but also because of the high cost effectiveness of their production. It is desirable to use all the knowledge gained during the development and optimization of Single-Walled Carbon Nanotubes production to control the structure of catalytically synthesized Multi-Walled Carbon Nanotubes. In this work the transition between CoMoCAT® and highly selective catalysts for the production of Multi-Walled Carbon Nanotubes is shown.

As mentioned before, it is important to produce Carbon Nanotubes not only at a high rate but also with high selectivity. In order to quantify the selectivity, different studies have been conducted using a variety of analytical techniques. The advantages and disadvantages of widely used metrology techniques are analyzed and shown in this work. A new quantitative method to measure the SWCNT selectivity is also presented here.