Single-wall carbon nanotubes synthesized using organic additives to Co-Mo catalysts supported on nanoporous MgO

Abstract

Carbon nanotubes (CNTs) were synthesized by catalytic decomposition of<br>20% methane in hydrogen over Co–Mo/MgO catalysts at 1000 ◦C. The<br>catalysts were prepared by a modified sol–gel method, using sorbitol,<br>ethylenediamine tetraacetic acid (EDTA), tartaric acid and citric acid as<br>organic additives. The specific surface area (SSA) of the catalysts changes<br>with the organic additives in the order of sorbitol &gt; EDTA &gt; citric acid &gt;<br>tartaric acid. As a result the crystallite size, dispersion of Co–Mo and hence<br>the quality of the carbon nanotubes change with the organic additive. Up to<br>180 wt% yield of high quality single-wall carbon nanotubes (SWNTs) with<br>inner-wall diameter close to 1.0–1.2 nm are obtained on the catalyst prepared<br>in the presence of sorbitol.