多级孔钛硅分子筛制备及其催化羟基化性能

Preparation and catalytic hydroxylation performance of hierarchical titanium silicalite-1

通过溶胶-凝胶法,以十六烷基三甲基溴化铵(CTAB)为模板剂,合成了多级孔钛硅分子筛(h-TS-1)。运用透射电子显微镜(TEM)、X射线衍射(XRD)、氮气等温吸附-脱附、紫外-可见漫反射光谱(DR UV-Vis)和傅里叶红外光谱(FT-IR)对h-TS-1的结构进行了表征;考察了h-TS-1在温和条件下用过氧化氢作氧化剂对直接羟基化苯和苯酚反应的催化活性。结果表明:h-TS-1除具有和TS-1相同的MFI结构和良好的晶型外,还同时具有微孔和介孔结构,平均孔径为2.67 nm;h-TS-1对目标反应的催化活性明显优于TS-1;h-TS-1具有良好的可重复利用性。

Hierarchical titanium silicalite-1(h-TS-1) was synthesized by sol-gel method with cetyltrimethyl-ammonium bromide(CTAB) as mesopores template.Structural features of the h-TS-1 were characterized by transmission electron micro- scope(TEM),X-ray diffraction(XRD),N2 adsorption-desorption,ultraviolet-visible diffuse reflectance spectroscopy(DR UV-vis) and Fourier transform infrared spectroscopy(FT-IR).Catalytic performance of the h-TS-1 was investigated by the direct hydroxylation of benzene and phenol,using H2O2 as oxidant under mild conditions.The results indicated that the h-TS-1 not only possessed the same MFI topology and ideal crystal form as TS-1,but also had microporous and mesoporous structure,of which the average pore size was 2.67 nm.Compared with TS-1,the catalytic activity of h-TS-1 had been improved significantly.Furthermore,the h-TS-1 had a great capacity of reutilization.