Preparation of large particle MCM-41 and investigation on its fluidization behavior and application in single-walled carbon nanotube production in a fluidized-bed reactor

Large particle MCM-41 was synthesized using preshaped silica gel as the silica source. The physical properties of MCM-41 samples were characterized by X-ray diffraction (XRD), nitrogen physisorption, and field emission scanning electron microscopy (FESEM). The sample showed highly ordered mesoporous structure and spherical morphology with particle sizes of 20–45 μm by pseudomorphic synthesis. The fluidization study showed that the MCM-41 with large particle size, for the first time, can be well fluidized because of the transformation from Geldart C to Geldart A classification. Furthermore, Co–Mo catalyst using large particle MCM-41 as support was successfully applied for the synthesis of single-walled carbon nanotubes (SWCNTs) in a fluidized-bed reactor. The product was monitored by thermogravimetric analysis (TGA), transmission electron microscopy (TEM), Raman and Fluorescence spectroscopy, which suggested the resulted semiconducting SWCNTs possess the narrow (n, m) distribution.