氧化铜催化五氯苯生成二噁英的研究  

PCDD/Fs Formation from Pentachlorobenzene Under the Catalysis of CuO

作　　者：杜永光[1] 张海军[1] 陈吉平[1] 樊芸[1] 倪余文[1] 

机构地区：[1]中国科学院大连化学物理研究所,大连116023

出　　处：《环境科学》2010年第11期2774-2779,共6页Environmental Science

基　　金：国家重点基础研究发展规划(973)项目(2009CB421606);国家自然科学基金项目(20977091);国家科技支撑计划项目(2008BAC32B03);中国科学院知识创新工程领域前沿项目(K2007C1)

摘　　要：研究在加热条件下,五氯苯在CuO表面催化生成二噁英(PCDD/Fs)的过程.结果表明,在200～350℃,PCDD/Fs的生成量随温度的升高而增加;在350～450℃,PCDD/Fs的生成量随温度的升高而减少.温度较低时(200～250℃),生成的PCDD/Fs以高氯取代同系物为主;温度较高时(400～450℃),则以低氯取代的同系物为主.但温度的改变并没有引起同一氯取代度PCDD/Fs中的异构体分布模式发生规律性变化.通过比较400℃条件下CuO催化五氯苯生成PCDD/Fs与CuO催化OCDD/F的脱氯降解情况,推测了五氯苯生成PCDD/Fs的途径.低氯取代的PCDDs可能主要来源于五氯苯生成的高氯取代PCDDs的进一步脱氯降解.而PCDFs则主要由五氯苯脱氯降解生成的低氯取代产物直接缩合生成.The formation processes of PCDD /Fs from pentachlorobenzene catalyzed by CuO under heating conditions were investigated.The results showed that,the amount of the formed PCDD /Fs increased with the temperature from 200℃ to 350℃,and then decreased with futher increase of temperature from 350℃ to 450℃.PCDD /Fs homologue pattern varied significantly according to the reaction temperature.At the lower temperature（200-250℃）,the major PCDD /Fs products were highly chlorinated ones;but at the higher temperature（400-450℃）,the low chlorinated PCDD /Fs predominated in the PCDD /Fs products.The change of temperature did not cause a systematical variation in the isomer distributions in each PCDD /Fs homologue.By comparing the formation of PCDD /Fs from pentachlorobenzene with the dechlorination of OCDD /F both under the catalysis of CuO at 400℃,the precursor mechanism of PCDD /Fs formation from pentachlorobenzene was speculated.Low chlorinated PCDDs mainly came from the dechlorination of highly chlorinated PCDDs which were formed from the pentachlorobenzene,whereas PCDFs could be mainly formed by the direct condensation of dechlorination products of pentachlorobenzene.

关 键 词：五氯苯 氧化铜 二噁英 前体物 

分 类 号：X705[环境科学与工程—环境工程]