利用单壁碳纳米管(SWNTs)自身的还原性,将PdCl2溶液中的Pd^2+直接还原成金属Pd负载在SWNTs表面上,制备了具有良好催化性能的Pd/SWNTs负载型催化剂.通过透射电镜(TEM)、X射线衍射(XRD)、X射线光电子能谱(XPS)和热重分析fiG)对Pd/SWNTs进行了表征,并利用Suzuki反应对Pd/SWNTs的催化性能进行了测试.实验结果表明,用SWNTs与12mmol·L^-1的PdCl。的水溶液直接作用,得到Pd/SWNTs催化材料的Pd负载量达到14.13%(w,质量分数),颗粒分散均匀,粒径小(2nm左右),与SWNTs结合紧密;用经过H2还原的Pd/SWNTs作催化剂,在90℃下进行Suzuki反应,30min后反应就基本完成,其联苯的产率达到98.10%,催化活性较高,可望广泛用于有机合成反应.
A Pd catalyst supported by single-walled carbon nanotubes (SWNTs) was prepared by a redox reaction between SWNTs and PdC12 solution. The supported catalyst was characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and thermo-gravimetric (TG) techniques. Results showed that large quantities of Pd particles with diameters of ca 2 nm distributed evenly on the surface of SWNTs and the content of Pd was 14.13% (w, mass fraction) when using SWNTs and 12 mmol·L^-1 PdCl2 as reactants. The supported catalyst, after reduction by H2, exhibited high catalytic activity in Suzuki reaction. The yield of biphenyl was 98.10% after 30 min reaction at 90 ℃.