高聚物负载型双金属催化剂催化氢转移有机卤化物脱卤

Synergistic Effect of Polymer Supported Bimetallic Catalyst for Hydrogen Transfer Dehalogenation of Organic Halides

以甲酸钠为氢转移试剂 ,以聚乙烯基吡咯烷酮负载PdCl2 和其它金属盐制成双金属催化剂PVP PdCl2 MXn,用于催化有机卤化物脱卤 .与负载型单金属催化剂PVP PdCl2 相比 ,PVP PdCl2 CdCl2 和PVP PdCl2 HgCl2 对氯代芳烃脱氯有高得多的催化活性和脱氯选择性 ,且偶联副产物显著减少 ;以对氯苯胺为底物时 ,双金属催化下的反应时间缩短为单金属催化下的 1 /8,而脱氯产物收率提高 2 5倍 ;底物为对氯甲苯时 ,双金属催化下的偶联副产物仅为单金属催化下的 1 /390 .用IR和TEM技术对PVP负载型金属催化剂进行了表征 。

The catalytic behavior of PVP supported bimetallic catalyst, made of PdCl 2 and other metal salts, for the dehalogenation of organic halides with sodium formate as hydrogen transfer reagent was studied. It was found that the samples PVP PdCl 2 CdCl 2 and PVP PdCl 2 HgCl 2, compared with PVP PdCl 2, exhibited much higher catalytic activity and dechlorination selectivity, and the yields of the coupling by products were obviously decreased. For example, when p chloroaniline was used as substrate, the reaction time was shortened to 1/8, and the yield of dechlorination product was about 25 times as much as the original one, and when p chlorotoluene was used as substrate, the yield of coupling by product catalyzed by bimetallic catalyst was 1/390 of that catalyzed by monometallic catalyst. A preliminary discussion on the possible synergic effect of bimetallic catalyst has also been made.