Carbon Nanotube Synthesis Using Fe‐Mo/MgO Catalyst with Different Ratios of CH4 and H2 Gases

The huge molecular cluster {Fe30Mo72} has been used as a source of catalyst nanoparticles in catalytic chemical vapour deposition (CCVD) process of carbon nanotubes (CNTs) synthesis. Thermal decomposition of {Fe30Mo72} in air is shown by X‐ray diffraction analysis to produce iron molybdate, which is converted to alloyed Fe‐Mo and Fe nanoparticles at elevated temperature and reduction environment. These nanoparticles supported on MgO, catalyse the growth of single‐walled, double‐walled and/or multi‐walled CNTs depending on the active metal loading and ratio of methane and hydrogen in the feedstock. The structural parameters of the products are studied by transmission electron microscopy and Raman spectroscopy. The best CNT samples are tested as field electron emitters. Thermal decomposition of {Fe30Mo72} clusters in a reducing atmosphere produces Fe and Fe‐Mo nanoparticles uniformly distributed on MgO support. Depending on active metal loading on the support and addition of hydrogen into methane flow, these nanoparticles catalyze the growth of solely MWCNTs or different CNTs, where the number of walls varies from one to few.