Fabrication And Catalytic Performance Of Dual-functionalized Platelet SBA-15Solid Acids

Since the mesoporous silica of high surface area and highly ordered uniform pores such as SBA-15of hexagonal-ordered pore structure, was synthesized using amphiphilic triblock copolymers as the pore-directing agents,It has received great attention and shown great importance in catalysis,sorption,and immobilization of biomolecular and functional materials in recent years because of its relatively large pore diameter and high hydrothermal stability.Not only the pore structure but also the morphology of the SBA-15matters in its applications.The morphology of typical SBA-15was fiber-like and its pore length-fiber length is over10μm,which makes the transition and diffusion difficult and slowly especially for large molecules. That makes the well-formed monodisperse hexagonal platelet SBA-15which pore length is about300nm-500nm more preferable especially in the practical applications.In this paper,firstly the hexagonal platelet SBA-15with short channels(300nm)was prepared using amphiphilic triblock copolymers P123as structure-direction agents,TEOS as the precursor,by introducing Zr4+.Then the monodisperse platelet SBA-15without eliminating P123was carbonized in high temperature under N2environment to obtain silica/carbon nanocomposite,then the silica/carbon particles were sulfonated in20vol.%fuming H2SO4to obtain platelet SO3H-bearing carbon/SBA-15.The Structural information of the prepared nanocompositeswas obtained using scanning electron microscopy SEM(JSM-6460LV),small angle X-ray diffraction(XD-3A),Fourier transform-infrared(FT-IR Spectrum One-B) spectroscopy,N2adsorption analysis(NOVA2200e).And the result show that the ratio of Zr/Si and the prehydrolyzation time of ZrOCl2·8H2O were essential to successfully synthesize monodisperse hexagonal platelet SBA-15with short pore channel,And the morphology was remained after carbonation and sulfonation.The obtained platelet SO3H-bearing carbon/SBA-15were used as catalysis of esterification between oleic acid and methanol studied its catalytic properties。And the reaction conditions were optimized which is Wcatalyst/Wreactant=5%,T=80℃, methanol/oleic acid(mol)=20:1,reaction time=8h.The conversion of oleic acid was85.4% catalyzed by the obtained platelet SO3H-bearing carbon/SBA-15while the fiber-like SO3H-bearing carbon/SBA-15was just about75%,which showed that the platelet carbon/SBA-15has excellent catalytic properties.And it is expected to be useful in different applications like immobilization of biomolecular or other fields.