论文部分内容阅读
以1,4-双(三乙氧基硅基)苯和苯基膦钯有机金属硅烷为混合硅源,在表面活性剂导向组装下共缩聚制得Pd(Ⅱ)-PMO-KIT-6非均相催化剂,并利用NMR、XPS、XRD、TEM和氮气吸附等手段对催化剂进行了表征.考察了该催化剂在水介质Sonogashira反应中的催化性能,结果表明:所制备的Pd(Ⅱ)-PMO-KIT-6具有优异的催化活性和选择性,这主要归因于催化剂的高比表面积、双连续介孔结构有利于提高Pd(Ⅱ)活性位分散度,减少传质阻力;同时苯基桥联PMO构建形成的微环境增强表面疏水性,有利于反应底物的吸附和扩散.此外,催化剂还可以重复使用多次后活性没有明显降低.
Pd (Ⅱ) -PMO-KIT-6 was synthesized by copolycondensation of 1,4-bis (triethoxysilyl) benzene and phenylphosphine palladium organosilane as the mixed silicon source under the guidance of surfactant. The catalysts were characterized by means of NMR, XPS, XRD, TEM and N2 adsorption. The catalytic performance of the catalyst in Sonogashira reaction was investigated. The results showed that Pd (Ⅱ) -PMO -KIT-6 has excellent catalytic activity and selectivity, which is mainly attributed to the high specific surface area of the catalyst. The bicontinuous mesoporous structure is conducive to improving the Pd (Ⅱ) active site dispersion and reducing the mass transfer resistance. Meanwhile, the phenyl bridge The microenvironment formed by the combination of PMO enhances the surface hydrophobicity, which is conducive to the adsorption and diffusion of the reaction substrate.In addition, the catalyst can be repeatedly used for many times without significant reduction in activity.