催化降解因其高的反应速率和降解彻底性,在氯代有机物的削减中得到广泛应用.目前研究较多的催化剂为零价态和氧化态的碱金属和碱土金属、过渡金属及贵金属,包括单金属和双金属两种.这类催化剂表面活性位点多样,在氯代有机物的降解中显示出优异的活性.多氯联苯(Polychlorinated Biphenyls,简称PCBs)是一类有毒难降解的持久性有机污染物.本文阐述了不同价态的单金属和双金属催化剂催化降解PCBs的反应机理,并介绍了影响反应速率和产物选择性的因素.并对金属及其氧化物催化降解PCBs的应用现状做了评述,对该技术的发展进行展望.
Catalytic destruction is a widely used method in the degradation of chlorinated organic materials because of its high reaction rate and ability to achieve complete degradation.Monometals and bimetals of alkali metals,alkaline earth metals,transition metals,and noble metals,are currently used as catalysts,in their zerovalent and/or other oxidation states.Since these catalysts have a variety of surface active sites,they show good activities in the degradation of chlorinated organic materials.This paper reviews a wide range of catalytic decompositions of polychlorinated biphenyls(PCBs) by monometals and bimetals in different valence states,and the decomposition reaction mechanisms.The effects of reaction conditions on degradation efficiency and product selectivity are discussed.Furthermore,the applications of metal and metal oxide catalysts in PCB destruction are evaluated,and future developments of this technique are proposed.