Ti-MCM-41的结构特征与芳烃羟化反应的化学亲和选择性

STRUCTURAL CHARACTERISTICS OF Ti-MCM-41 AND THE CHEMISTRY SELECTIVITY IN THE HYDROXYLATION OF BENZENE

以不同硅源合成了Si Ti比不同的Si Ti MCM 41,并在引入Ti的同时引入Al,合成了Si Al比不同的Si Ti Al MCM 41。XRD、TEM、低温N2 吸附的表征结果说明 ,Ti MCM 41具有长程有序一维孔道 ,且比表面积较高。FT IR光谱表征说明 ,Ti对骨架Si的取代使MCM 41表面出现缺陷羟基。Al的引入有利于Ti MCM 41有序结构的形成 ,且可调变Ti MCM 41的表面性质。Ti MCM 41在不同极性芳烃化合物的羟化过程中表现出化学亲和选择性 ,且调变Ti MCM

Ti MCM 41 with different Si/Ti has been synthesized using various Si sources, and Al containing Ti MCM 41 with different Si/Al has also been obtained by inserting Al along with Ti The results obtained by XRD, TEM and N 2 adsorption at low temperature show that Ti MCM 41 possesses ordered one dimensional channels and high specific area, and the insertion of Al favors the formation of ordered structures The surface properties of MCM 41 are altered by the insertion of Ti and can be further modified through introducing Al Si Ti MCM 41 significantly favors the hydroxylation of benzene over the hydroxylation of phenol, thereby showing the potential for enhanced chemical selectivity for the hydroxylation of aromatics The hydroxylation of benzene takes place more readily with decreasing Al content and the hydroxylation of phenol proceeds more readily with increasing Al content, indicating that the chemistry selectivity can potentially be altered by changing the surface properties of the catalyst