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以PPh2C2H4-Si(OEt)3和(EtO)3Si-C2H4-Si(OEt)3为混合硅源,在表面活性剂作用下共缩聚制备有序介孔有机硅杂化材料,再络合Pd(Ⅱ)离子得到固载化Pd(Ⅱ)非均相催化剂.在水介质Barbier反应中,所制备的Pd(Ⅱ)-PPh2-PMO(Et)具有与均相Pd(PPh3)2Cl2催化剂相当的催化活性,主要归因于高比表面积、有序介孔结构,有利于提高Pd(Ⅱ)活性位分散度,减少传质阻力,同时乙基修饰孔壁增强表面疏水性,有利于有机分子在孔道内的扩散和活性位上的吸附,导致高催化活性,而且可重复使用,显示了良好的工业应用前景.
The ordered mesoporous organosilicon hybrid materials were prepared by co-condensation of PPh2C2H4-Si (OEt) 3 and (EtO) 3Si-C2H4-Si (OEt) Ⅱ) Pd (Ⅱ) -catalyzed Pd (Ⅱ) -PPh2-PMO (Et) was prepared by catalytic hydrogenation in the Barbier reaction of aqueous medium Activity is mainly due to the high specific surface area and ordered mesoporous structure, which is favorable for improving the Pd (Ⅱ) active site dispersion and decreasing the mass transfer resistance. Meanwhile, the ethyl-modified pore walls enhance the surface hydrophobicity and are favorable for the formation of organic molecules in pores The diffusion within the track and adsorption on the active site lead to high catalytic activity, and can be reused, showing a good prospect for industrial applications.