催化学报

催化学报 ›› 2006, Vol. 27 ›› Issue (4): 339-343.

• 研究论文 • 上一篇    下一篇

Pd/NH2C3H6-MCM-41催化水介质中的碘苯Ullmann反应

陈佳,万颖,李和兴   

  1. 上海师范大学化学系, 上海 200234
  • 收稿日期:2006-04-25 出版日期:2006-04-25 发布日期:1984-12-26

Ullmann Reaction of Iodobenzene over Pd/NH2C3H6-MCM-41 in Aqueous Medium

CHEN Jia, WAN Ying, LI Hexing*   

  1. Department of Chemistry, Shanghai Normal University, Shanghai 200234 , China
  • Received:2006-04-25 Online:2006-04-25 Published:1984-12-26

PDF

713

被引次数

10

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.

关键词: 钯, 负载型催化剂, 改性, MCM-41沸石, Ullmann反应, 碘苯, 联苯

Abstract: 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[KG-47x]-[KG-15x][KG*2] 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.

Key words: palladium, supported catalyst, modification, MCM-41 zeolite, Ullmann reaction, iodobenzene, biphenyl