Fe₃O₄を内包するSBA-15の試作と触媒材料への応用

抄録

Because of thermal stability, tunable porosity and modifiable surface, mesoporous silica is a promising material in catalysis, drag delivery and environmental applications. These industrial potentials could be enhanced by compounding mesoporous silica with Fe₃O₄ nano-particles, since its para-magnetism brings about the spatial mobility controlled under magnetic field. For the present research work, tetraethylorthosilicate was hydrolyzed and poly-condensed over the self-assembled surfactant micelles in the presence of Fe₃O₄ nano-particles in order to embed it in mesoporous silica SBA-15. Under the acidic condition caused by an aqueous solution of FeCl₃, the poly-condensates were formed into the well-ordered hexagonal arrays of one-dimensional channels without dissolution of Fe₃O₄ nano-particles. This was the first successful synthesis of SBA-15 in which Fe₃O₄ nano-particles were embedded. On the other hands, another approach where SBA-15 was synthesized over Fe₃O₄ coated with amorphous silica in HCl aqueous solution ended in failure because the coated silica could not prevent Fe₃O₄ from dissolving in HCl aqueous solution. For the SBA-15/Fe₃O₄ composite prepared successfully, a quaternary alkyl-ammonium salt was grafted in order to prove the catalytic application.