介孔Ti-MCM-41在苯乙烯氧化反应中的催化性能

Catalytic Performance of Ti-MCM-41 for Styrene Oxidation

以MCM-41为骨架,以无机钛源Ti(SO4)2为原料成功合成了不同Ti含量的Ti-MCM-41样品,并考察了它们在H2O2氧化苯乙烯反应中的催化性能,研究了溶剂和Ti含量等因素对其催化性能的影响.结果表明,该反应主要产物为苯甲醛,苯乙烯转化率和苯甲醛收率均随骨架Ti含量增加而增加;催化剂中钛含量相近时,孔径的减小能够改善其催化性能;反应体系的合适溶剂应具有一定极性,如乙腈;降低溶剂极性和H2O2浓度可减少苯乙烯的进一步氧化,从而适当增加了苯乙醛和环氧苯乙烷选择性.

A series of Ti-MCM-41 samples with different titanium contents in the MCM-41 framework were synthesized using Ti（SO4）2 as the titanium source. Their catalytic performance in the direct oxidation of styrene with hydroperoxide was studied. The effects of the solvent kinds and titanium content on the catalytic activity of Ti-MCM-41 were also investigated. The results indicated that benzaldehyde was the main product, and both the styrene conversion and benzaldehyde yield increased with increasing titanium content in the framework. The catalytic activity increased with the decrease of the pore size of the catalyst. Organic compounds with proper polarity such as acetonitrile were the suitable solvent. The further oxidation of styrene can be cut down by decreasing solvent polarity and H2O2 concentration, and thus the selectivity for styrene epoxide and hyacinthin increased.