SBA-15负载CeO2纳米晶的溶胶-凝胶一步合成

以P123为模板剂, 正硅酸乙酯和硝酸铈为前驱体, 通过溶胶-凝胶路线在酸性条件下合成了SBA-15负载氧化铈(CeO2与SiO2质量比为28.7%)有序介孔材料. 采用热重/差热分析(TGA/DTA)、X射线衍射(XRD)、透射电镜(TEM)和氮气吸附等手段对所合成材料进行了表征. 结果表明, 合成的材料具有类似于SBA-15的结构, 孔径、孔容和比表面积分别为38.7 Å, 0.46 cm3/g和570 m2/g. X射线衍射(XRD)、透射电镜(TEM)、X射线能谱(EDS)和选区电子衍射花样联合表征证实了铈物种以高分散的CeO2纳米晶的形式分布在介孔基体中.

Synthesis of SBA-15 Loaded CeO2 Nanocrystals via Sol-gel One-step Process

Ordered mesoporous SBA-15 silica loaded with ceria at a mass ratio of CeO2/SiO2＝28.7% was synthesized by a sol-gel route using Pluronic P123 as a template, tetraethyl orthosilicate as a silica source and hydrated cerium nitrite as a precursor under an acidic condition. The as-synthesized materials were characterized by thermogravimetric analysis/differential thermal analysis, X-ray diffraction, transmission electron microscopy, and N2 adsorption. Characterization revealed that the as-synthesized materials possessed an ordered hexagonal mesoporous structure similar to SBA-15. The average pore size, pore volume and specific surface area of the materials is 38.7 Å, 0.46 cm3/g and 570 m2/g, respectively. The fact that cerium species are present as highly dispersed CeO2 nanocrystals in a hexagonal matrix was confirmed by combined characterization of XRD with high-resolution TEM, selected area electron diffraction analysis and EDS.