CAJ | 학술논문

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Pd~0和Pd~(2+)的形式分散在CNTs表面,粒径大小为10 nm.在空气气氛中,Pd/CNTs催化剂用胃(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.
채용침지회류법제비료탄납미관(CNTs)부재적납미Pd최화제(Pd/CNTs),통과ICP、XPS화TEM등수단대기진행료표정,병용우전분적Heck반응.결과표명,Pd/CNTs최화제중Pd적부재량위0.24%시,Pd이Pd~0화Pd~(2+)적형식분산재CNTs표면,립경대소위10 nm.재공기기분중,Pd/CNTs최화제용위(이Pd재전분중적마이분수x(Pd)표시)위0.004시,즉가유효최화전분여병희산적반응,육계산산솔위62.5%.해최화제중복사용4차후,최화활성몰유명현강저.
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.