摘要
采用Pd/Fe双金属体系在常温常压下对二氯苯的3种同分异构体进行了快速催化还原脱氯的研究。通过原始污染物和产物的变化,重点考察取代基位置以及pH值等因素对脱氯反应的影响。结果表明,反应条件一致时,氯取代基位置对脱氯有一定的影响。还原脱氯的速率1,2-DCB>1,3-DCB>1,4-DCB。酸性环境有利于二氯苯脱氯。二氯苯在催化脱氯的过程中依次脱氯成为氯苯和苯。当二氯苯类化合物浓度约为0.45mmol·L-1,0.03%Pd/Fe加入量为1g·40mL-1氯苯,25℃条件下,经过90min反应,3种二氯苯的还原率均在80%以上。
Pd/Fe bimetal catalysts were utilized for the reductive dechlorination of the isomers of dichlorobenzene （DCB） in aqueous medium at ambient temperature and pressure. Factors influencing the removal of chlorinated dichlorobenzene were studied by the contrast of original pollutant and product. Batch experiments demonstrated the differences in the observed rate coefficients for the dechlorination reaction of the three isomers of DCB. The positions of chlorine on the benzene ring and the initial pH seemed to affect the rates of the dechlorinaton, with the rates of 1,2-DCB 〉 1,3-DCB 〉1,4-DCB under almost identical conditions and acidic environment tended to facilitate the dechlorination re- action. GC-MS data revealed that chlorobenzene was the stable dechlorination intermediate, which was further dechlorinated to benzene as the final product. Dechlorination efficiency of all three isomers reached as high as 80% when one gram of the Pd/Fe catalysts containing 0.03% Pd by weight was added to 40 ml of the solution and allowed to react for 90 min at 25 ℃.
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2008年第2期758-761,共4页
Journal of Agro-Environment Science
基金
广东省科技攻关项目(2003C32910)
关键词
钯
铁双金属
零价铁
还原脱氯
二氯苯
Pd/Fe bimetal
zero-valent iron （ZVI）
reductive dechlorination
dichlorobenzene （DCB）
