原位漫反射红外光谱表征钛硅分子筛TS-1催化苯乙烯氧化反应

采用高温漫反射红外光谱考察了钛硅分子筛TS-1的稳定性，发现960 cm-1吸收峰在673 K时没有变化，表明所表征的骨架钛具有一定的高温稳定性，而表征分子筛骨架振动的两个吸收峰在673 K下向低波数位移了约13 cm-1。探讨了H₂O₂吸附对TS-1分子筛骨架钛的影响，发现960 cm-1处的吸收峰在吸附H₂O₂后强度减弱，并且向高波数位移了11 cm-1;抽真空或加热，吸收峰又复原，表明骨架钛可能存在TiO结构，H₂O₂与分子筛中的TiO作用，使相应的960 cm-1吸收峰向高波数位移。原位漫反射红外光谱考察了TS-1催化苯乙烯氧化反应，谱图分析表明，苯甲醛是主要产物，TS-1催化氧化的关键是H₂O₂吸附在TS-1的骨架钛上形成活性中心。

In situ Diffuse Reflectance FTIR Spectroscopy Characterization of Titanium Silicalite-1 Catalytic Oxidization of Styrene

The Stability of framework of titanium silicalite-1 (TS-1) was investigated by high temperature diffuse reflectance FTIR spectroscopy (DRIFTS), and the results showed that the 960 cm-1 peak belonging to Ti-framework was stabilized at 673 K, but the two peaks belonging to framework shifted to lower frequencies by about 13 cm-1 at 673 K. The effect on the framework after H2O2 adsorption was discussed. The results showed that the 960 cm-1 peak lowered and shifted to high frequencies by about 11 cm-1, but it recovered with vacuum or heating up. It was suggested that the 960 cm-1 peak characterizes TiO, and this explained why the 960 cm-1 peak shifted to high frequencies well. TS-1 catalytic oxidization of styrene was investigated by in situ DRIFTS. The reaction process was detected and phenyl aldehyde was the main product. Based on in situ analysis, it was proposed that H2O2 was adsorbed on Ti in framework of TS-1 to form active center.