Ti-HMS的合成和催化苯乙烯环氧化性能

Synthesis and Catalyzing Styrene Epoxidation of Ti-HMS

利用中性伯胺 (十二胺 )作模板剂 ,合成了过渡金属Ti取代的HMS中孔材料 .XRD和FT IR表征表明Ti能有效地嵌入HMS骨架壁中而不会造成其中孔有序度的下降 .钛在HMS中的嵌入量是随合成原料n(Ti) /n(Si)的增加而上升的 ,最高可达每克HMS嵌入 1 6 1mmol钛 .IR中 96 0cm-1带强度与钛嵌入量呈正比 ,这可能表明 96 0cm-1是由钛嵌入中孔骨架而引起硅氧四面体结构发生畸变所致 .催化实验结果表明 :Ti HMS能有效催化叔丁基过氧化氢 (TBHP)氧化苯乙烯生成环氧苯乙烷 (6 5 %～ 86 %) ,苯乙醛 (6 %～ 15 %)和苯甲醛 (8%～ 2 0 %) ,且能重复使用数次而不失活 ,此外催化剂的制备条件和反应条件对其催化活性和产物分布也有不同程度的影响 .

XRD and IR show that titanium is effectively embedded into framework of HMS, and the order degree of mesoporous HMS doesn't fall down. Embedding content of Ti corresponds well with n(Ti)/n(Si), and the most one is up to 1.61 mmol Ti per g HMS. The intensity of 960 cm 1 band on the IR spectra of Ti-HMS samples takes direct proportion to embedding Ti content. It is shown that this peak may be caused with distortion of SiO4 tetrahedron that titanium atom incorporate into the mesoporous framework. In catalyzing the epoxidation of styrene, Ti-HMS catalyst can effectively catalyze the oxidation of styrene by TBHP into styrene oxides (65% ∼ 86%), phenylacetaldehyde (6% ∼ 15%) and benzaldehyde (8% ∼ 20%). Be used repeatedly without to be loss of activity. The preparation and reaction conditions of Ti-HMS have the different influences on its catalytic activity and product selectivity.