碳纳米管负载纳米钯催化Heck的反应

PERFORMANCE OF CARBON NANOTUBES SUPPORT NANO-PALLADIUM CATALYST FOR HECK REACTION

采用浸渍回流法制备了碳纳米管(CNTs)负载的纳米Pd催化剂(Pd/CNTs),通过ICP、XPS和TEM等手段对其进行了表征,并用于碘苯的Heck反应。结果表明,Pd/CNTs催化剂中Pd的负载量为0.24%时,Pd以Pd0和Pd2+的形式分散在CNTs表面,粒径大小为10nm。在空气气氛中,Pd/CNTs催化剂用量(以Pd在碘苯中的摩尔分数x(Pd)表示)为0.004时,即可有效催化碘苯与丙烯酸的反应,肉桂酸产率为62.5%。该催化剂重复使用4次后,催化活性没有明显降低。

Nano-palladium catalyst supported by carbon nano-tubes （Pd/CNTs） for iodobenzene Heck reactions was prepared with impregnation method and characterized by ICP, XPS and TEM techniques. The results showed that there were two chemical states （zero-valent and divalent） for Pd existing on CNTs surface, with the particle size of about 10 nm when Pd loading in the Pd/CNTs catalyst was 0. 24% . In the air atmosphere, when x （Pd） （molar fraction of Pd in iodobenzene） was 0. 004, the Heck reaction between iodobenzene and acrylic acid could be catalyzed effectively by the Pd/CNTs catalyst with 62. 5% yield of cinnamic acid. The catalyst could be reused 4 times without loss of catalytic activity.