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.