Thermal dechlorination of PCB-209 over Ca species-doped Fe2O3

CORC > 生态环境研究中心 > 中国科学院生态环境研究中心 > 环境化学与生态毒理学国家重点实验室

	Thermal dechlorination of PCB-209 over Ca species-doped Fe2O3
	Su, Guijin; Huang, Linyan; Shi, Ruifang; Liu, Yexuan; Lu, Huijie; Zhao, Yuyang; Yang, Fan; Gao, Lirong; Zheng, Minghui
刊名	CHEMOSPHERE
	2016-02
卷号	144 期号:0 页码:81-90
关键词	Ca species-doped Fe2O3 Polychlorinated biphenyls Hydrodechlorination Steric effect
英文摘要	Degradation reaction of decachlorobiphenyl (PCB-209) was investigated over the synthesized Ca speciesdoped Fe2O3 at 300 degrees C. The 1%Ca-Fe2O3 exhibited the highest activity among the four catalysts prepared with the pseudo-first order reaction at k(obs) = 0.103 min(-1). PCB-207, PCB-197, PCB-176, PCB-184, PCB-150, PCB-136, PCB-148, PCB-104, PCB-96, PCB-54, PCB-19, PCB-4 and PCB-1 were identified as the dominant isomers in their respective nonachlorobiphenyl (NonaCB) to monochlorobiphenyl (MonoCB) homologue groups. Analysis of the hydrodechlorination products indicated that dechlorination was much more favored on meta-and para-than on ortho-positions. The formation of significantly predominant NonaCB and octachlorobiphenyl (OctaCB) isomers was attributed to lower energy principles and to the 90 degrees dihedral angles of two aromatic rings which prevented the hydrodechlorination at ortho-positions. When the number of chlorine atoms is not more than 7, the steric effect supports the formation of predominant PCB isomers having chlorines at four ortho-positions. During the dechlorination of tetrachlorobiphenyl (TetraCB) formed to generate monochlorobiphenyl (MonoCB) isomers, the chlorine atoms fully substituted at the ortho-positions have to be successively removed, with the first two dechlorinations preferentially occurring at the two different benzene rings. This is dissimilar to that of octachloronaphthalene (PCN-75) in which the hydrodechlorination reaction happened preferentially at ortho-position due to the existence of steric effects. The opposite roles of the steric effect in ortho-position between PCB-209 and PCN-75 might be due to the difference of the pi-conjugated plane caused by the dihedral angle of 90 degrees and 0 degrees of the two aromatic rings.(c) 2015 Elsevier Ltd. All rights reserved.
收录类别	SCI
内容类型	期刊论文
源URL	[http://ir.rcees.ac.cn/handle/311016/35964]
专题	生态环境研究中心_环境化学与生态毒理学国家重点实验室
推荐引用方式 GB/T 7714	Su, Guijin,Huang, Linyan,Shi, Ruifang,et al. Thermal dechlorination of PCB-209 over Ca species-doped Fe2O3[J]. CHEMOSPHERE,2016,144(0):81-90.
APA	Su, Guijin.,Huang, Linyan.,Shi, Ruifang.,Liu, Yexuan.,Lu, Huijie.,...&Zheng, Minghui.(2016).Thermal dechlorination of PCB-209 over Ca species-doped Fe2O3.CHEMOSPHERE,144(0),81-90.
MLA	Su, Guijin,et al."Thermal dechlorination of PCB-209 over Ca species-doped Fe2O3".CHEMOSPHERE 144.0(2016):81-90.