摘要
采用室温共缩聚法合成了胺基改性MCM-41杂化材料(NH2C3H6-MCM-41),并以此材料为载体制备了负载型Pd催化剂(Pd/NH2C3H6-MCM-41).采用X射线衍射、核磁共振、红外光谱、透射电镜、X射线光电子能谱和N2吸附等方法对催化剂进行了表征.结果表明,催化剂仍保持有MCM-41的孔结构,但其有序度随着NH2C3H6-基团和Pd含量的增加而降低.催化剂在以水为溶剂的碘苯偶联反应(Ullmann反应)中显示出优良的催化性能,联苯收率可达63%,有望为清洁有机合成提供高效非均相催化剂.胺基修饰的促进作用可归因于催化剂Pd分散度的提高和表面化学性质的改变.
NH2C3H6 modified MCM-41 was synthesized by co-condensation of tetraethylorthosilicate （TEOS） and organosilane aminopropyltrimethoxysilane （APTES） at room temperature, and it was then used as the support to prepare the Pd/NH2C3H6-MCM-41 catalyst. The characterization by X-ray diffraction, NMR, FT-IR, transmission electron microscopy, X-ray photoelectron spectroscopy, and N2 adsorption revealed that both NH2C3H6 MCM 41 and Pd/NH2C3H6 MCM 41 remained mesoporous structure similar to that of MCM-41, but their degree of structrural order decreased with the increase in the amounts of the NH2C3H6- group and Pd. During the Ullmann reaction of Phi performed in an aqueous medium, Pd/NH2C3H6-MCM-41 exhibited higher activity and higher selectivity for biphenyl than Pd/SiO2 and Pd/MCM-41. This may be due to the high and homogeneous dispersion of Pd particles, electron enrichment of metallic Pd, well-ordered mesoporous structure, suitable base strength, and hydrophobicity. The yield of biphenyl could reach 63 % , showing good potential of the catalyst in industrial application.
出处
《催化学报》
SCIE
CAS
CSCD
北大核心
2006年第4期339-343,共5页
基金
国家自然科学基金资助项目(20377031
20407014)
上海市重点学科资助项目(T0402)
