Synthesis of Three-Dimensionally Ordered Macroporous Co/SiO2 Catalysts by Sol-Gel Method

Abstract

A preparation of novel cobalt-based catalyst on three-dimensionally ordered macroporous (3DOM) silica supporter using poly (methyl methacrylate) monolith as a template has been studied. Monodispersed PMMA colloids were synthesized via an emulsion polymerization, resulting in PMMA spheres with the diameter of 390-400 nm. Two processes were employed for the 3DOM Co/SiO2catalyst fabrications, a single-stage sol-gel synthesis (SG) and incipient wetness impregnation method (IM) on synthesized 3DOM SiO2. Both catalysts were characterized using X-ray Diffraction (XRD), X-ray Absorption Spectroscopy (XAS), Scanning Electron Microscope (SEM) and specific surface area analysis. The XRD and XAS results showed that the doped Co in the 3DOM Co/SiO2(SG) were the mix phase of Co(NO3)2and Co3O4, while, only Co3O4was found in the 3DOM Co/SiO2(IM). The SEM micrographs revealed that both catalysts feature periodic macroporous structure with mean pore diameter of 300-350 nm. Specific surface area of the 3DOM Co/SiO2(IM) and the 3DOM Co/SiO2(SG) catalysts are 195 m2/g and 286 m2/g, respectively.