制备高比表面多孔Ti-Si复合氧化物材料的新方法

Ti- Si复合氧化物多孔材料在异相催化、催化剂载体等方面引起了人们的普遍关注 .将具有痕量Ti的 Si O2 玻璃用于纤维、膜及光学玻璃的制造中 ,在较宽的温度范围内显现出较低的热膨胀系数 1] .特定组成的 Ti- Si复合氧化物在一些酸催化反应中具有相当的活性 2～ 6 ] ,如苯酚胺化、乙烯水合、丁烯异构化、 2 -异丙醇脱水、 1 ,2 -二氯乙烷分解等反应 .另一些组成的 Ti- Si复合氧化物多孔材料已被用于选择性氧化反应中 7] .Ti- Si复合氧化物的物理化学性能与材料自身的组成及均匀性有关 ,常规的制备方法有共沉淀法 2 ,3,5] 和溶胶 -凝…

A New Method for Preparing Porous Ti-Si Dioxide Composite with High Surface Area

Anew method named peptizinggelation method was used to synthesize TiSi dioxide composite, whose surface area is above 1000 m²/g. The character of this method is that Ti exists in the form of ion and ion cluster during the hydrolysis of Si(OC₂H₅)₄. This is the progress on the cohydrolysis of Si(OC₂H₅)₄and Ti(OC₄H₉)_4.During the calcination of gelation, Ti-O-Si was formed with Ti element in the situation of SiO₂crystal cell. This is confirmed by FTIRanalysis. TiSi dioxide composite with Ti molar fraction of 13.1% is mainly in the form of amorphous based on XRDanalysis, which reveals that TiSi dioxide composite is uniform in structure. Furthermore, extra Ti element presents on the surface layer of TiSi dioxide composite examined by Raman and EESanalysis. Owning to these two characters, TiSi dioxide composite prepared by peptizinggelation method becomes a good catalyst in the field of catalysis.