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采用双功能硅烷化试剂γ-氨丙基甲基二乙氧基硅烷(AMS),对(MCM-41)全硅介孔分子筛一步进行氨基官能团化和甲基疏水性修饰,然后将双水杨醛缩乙二胺合钴(Cosalen)通过氨基的轴向配位固载在修饰后的载体MCM-41上。X射线衍射和N2物理吸附/脱附的结果表明:经过AMS双功能硅烷化修饰以及固载Cosalen后载体的孔道结构保持良好。考察了硅烷试剂用量对硅烷化效率的影响,结果表明:当AMS的加入量为4.00mmol/g时,甲基修饰量达到1.95mmol/g;水和环己烷的静态吸附结果表明硅烷化修饰后,催化剂载体的疏水性明显增强。制得的催化剂应用于环己烷的分子氧氧化反应,130℃反应2h,环己烷转化率达到7.2%,环己醇和环己酮总选择性达到70.5%,较未经AMS修饰的催化剂Cosalen/MCM-41获得的醇酮总选择性提高了13%。
Aminofunctionalization and methylhydrophobic modification of (MCM-41) all-silico-mesoporous molecular sieves were carried out using bifunctional silylation reagent γ-aminopropylmethyldiethoxysilane (AMS) Cosalen was immobilized on the modified MCM-41 carrier by axial coordination of amino groups. The results of X-ray diffraction and N2 physisorption / desorption show that the pore structure of the carrier is well maintained after the AMS bifunctional silanization modification and the immobilization of Cosalen. The effect of the amount of silanes on the silanization efficiency was investigated. The results showed that the amount of methyl groups reached 1.95mmol / g when the amount of AMS added was 4.00mmol / g. The static adsorption results of water and cyclohexane showed that the silanization modification After the catalyst carrier hydrophobic significantly enhanced. The obtained catalyst was applied to the molecular oxygen oxidation of cyclohexane. The reaction was carried out at 130 ℃ for 2h, the conversion of cyclohexane reached 7.2%, the total selectivity to cyclohexanol and cyclohexanone reached 70.5%, which was higher than that of the catalyst without modification of AMS Cosalen / MCM-41 obtained aldehyde ketone total selectivity increased by 13%.