介孔材料负载杂多酸催化环酮Baeyer-Villiger氧化反应研究

Mesoporous Materials Supported Heteropoly Acids for Baeyer-Villiger Oxidation of Cyclic Ketones

通过直接合成法一步得到了介孔分子筛负载硅钨酸系列催化剂:HSi W/SBA-15,HSi W/MCM-41,HSi W/MCM-48。综合运用FT-IR、XRD、SEM及TEM测试手段对所得催化剂样品的结构进行了表征,结果表明此类催化剂不仅保留了杂多酸的Keggin型结构,也保持了介孔分子筛规则的孔道结构,且杂多酸在载体上高度分散。将此类催化剂应用于环酮类底物的Baeyer-Villiger反应,考察了催化剂的催化性能,结果表明,此类催化剂可作为某些环酮Baeyer-Villiger氧化反应的良好催化剂,且此类催化剂的重复使用性能较好。

The mesoporous molecular sieves（ SBA-15,MCM-41,MCM-48） incorporated with HSi W（ denoted as HSi W/SBA-15,HSi W/MCM-41,HSi W/MCM-48） were synthesized via a direct method. All of the samples were characterized by powder X-ray diffraction（ XRD）, scaning electron microscopy（ SEM）, transmmission electron microscopy（ TEM） and Fourier transform infrared spectroscopy（ FT-IR）,followed by the catalytic property tests. The characterization results approved that Keggin unit were retained and encapsulated into the pore of the mesoporous silica,and an ordered channels with homogeneous pore diameters was obtained in the materials. The results also showed that the HSi W was highly dispersed in the samples. In the catalytic investigation,the effect of oxidation conditions,such as solvent,reaction time,the amount of catalyst,and reaction temperature,were discussed. It was found that all the three catalysts showed high catalytic activity in the Baryer-Villiger oxidation of ketones,and many cyclic ketones were efficiently converted to the corresponding lactones and high selectivities under the optimum reaction conditions. Due to the successful supporting of the cative species,it was proved that all the samples can be reused in the oxidation.