Electrophilic chlorination of dibenzo-p-dioxin and dibenzofuran over composite copper and iron chlorides and oxides in combustion flue gas
Electrophilic chlorination of dibenzo-p-dioxin and dibenzofuran over composite copper and iron chlorides and oxides in combustion flue gas
复制标题
燃烧烟气中铜铁复合氯化物和氧化物对二苯并对二恶英和二苯并呋喃的亲电氯化反应
DOI：
10.1016/j.chemosphere.2020.127065
复制
发表时间：
2020
期刊：
影响因子：
8.8
通讯作者：
Chen Jiping
中科院分区：
文献类型：
--
作者：
Wang Dan;Zhang Haijun;Ren Meihui;Fan Yun;Gao Yuan;Lv Zhenzhong Yang;Yu Ying;Chen Jiping
二苯并二恶英（DD）和二苯并呋喃（DF）在铜和铁氯化物作用下的氯化反应直接导致了燃烧烟气中多氯二苯并二恶英（PCDD）和多氯二苯并呋喃（DF）的生成。采用HCl溶液浸渍法制备了一种Cu、Fe复合氯化物和氧化物（CuFe 9 O 9. 5Cl 10），以模拟燃烧烟气中Cu、Fe物种的共存状态。复合CuFe9O9.5Cl10在150-300 °C对DD/DF的亲电氯化反应有促进作用，其中在200 °C时活性最高。DD/DF氯化反应在惰性气氛下进行，5%O2气氛对DD/DF氯化反应最有利。DD/DF的亲电氯化反应主要发生在2，3，7，8位。Cu和Fe的氯化物和氧化物的混合不仅降低了DD/DF氯化反应的起始温度和活化能，而且产生了协同效应，加速了DD/DF的氯化反应。复合CuFe_9 O_（9. 5）Cl_（10）对DD/DF的氯化促进活性与复合Cu（0.2Cl_（1.6））相近，而比复合Fe（0.3Cl_（2.4））高2个数量级。PCDD/F同系物分布模式的比较表明，DD/DF氯化应该是燃烧烟气中Cl 1 −3DFs和Cl 1 −2DDs的主要来源。
Dibenzo-p-dioxin (DD) and dibenzofuran (DF) chlorination mediated by Cu and Fe chlorides can make a direct contribution to the formation of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in combustion flue gas. In this study, a kind of composite Cu and Fe chlorides and oxides (CuFe9O9.5Cl10) was prepared by impregnating oxides with HCl solution to imitate the coexistence status of Cu and Fe species in combustion flue gas. Composite CuFe9O9.5Cl10was active in promoting the electrophilic chlorination of DD/DF at 150–300 °C, with the highest activity at 200 °C. DD/DF chlorination could occur under inert atmosphere, and 5% O2atmosphere was most favorable for DD/DF chlorination. Electrophilic chlorination of DD/DF primarily favored at 2,3,7,8 positions. Hybridization of Cu and Fe chlorides and oxides not only decreased the starting temperature and activation energy of DD/DF chlorination, but also induced a synergistic effect for accelerating the chlorination of DD/DF. The measured activities of composite CuFe9O9.5Cl10for promoting the chlorination of DD/DF were near to those of composite Cu chloride and oxide (CuO0.2Cl1.6), whereas 2 orders of magnitude higher than those of composite Fe chloride and oxide (FeO0.3Cl2.4). Comparison of PCDD/F congener distribution patterns indicated that DD/DF chlorination should be a main source of Cl1−3DFs and Cl1−2DDs in combustion flue gases.