• 关键词：催化氧化  挥发性有机物(VOCs)  1,2-二氯乙烷  CeO₂  过渡金属氧化物  HZSM-5分子筛

• 基金项目：国家重点基础研究计划(973)项目(No. 2004CB719504)

• 薛晓敏
• 浙江大学催化研究所,杭州 310028

• 黄琴琴
• 浙江大学催化研究所,杭州 310028

• 周仁贤
• 浙江大学催化研究所,杭州 310028

• 摘要：采用浸渍法制备了不同过渡金属掺杂的MO_x-CeO₂/HZSM-5(M 分别表示Cr、Mn、Fe、Co、Ni和Cu)催化剂,研究了各催化剂对1,2-二氯乙烷(DCE)的催化降解性能.结果表明,过渡金属掺杂后,MO_x-12%CeO₂/HZSM-5催化剂催化氧化1,2-二氯乙烷(DCE)的活性明显提高.各催化剂(记为M-CeO₂/HZSM-5)对DCE的催化氧化活性顺序为:9%Ni-12%CeO₂/HZSM-5 > 9%Co-12%CeO₂/HZSM-5、9%Mn-12%CeO₂/HZSM-5 > 9%Cu-12%CeO₂/HZSM-5、9%Cr-12%CeO₂/HZSM-5 > 9%Fe-12%CeO₂/HZSM-5 >12%CeO₂/HZSM-5.掺杂Co、Mn和Cu的催化剂上产生了较多的C₂HCl₃和C₂Cl₄等多氯烃副产物,尤其9%Cu-12%CeO₂/HZSM-5催化剂上还产生少量的C₂H₂Cl₄,容易产生二次污染.9%Cr-12%CeO₂/HZSM-5催化剂具有良好的DCE催化降解性能,由于CrO_x与CeO₂之间的强相互作用,提高了活性氧物种的流动性,从而促进了DCE的脱氯降解和深度氧化.

• Abstract：The catalytic performance of MO_x-CeO₂/HZSM-5 (M= Cr, Mn, Fe, Co, Ni and Cu) catalysts prepared by an impregnation method were evaluated in the oxidation of 1,2-dichloroetane (DCE). The introduction of secondary transition-metal-oxide component can greatly improve the catalytic activity of CeO₂/HZSM-5 for DCE destruction. The catalytic activities of MO_x-CeO₂/HZSM-5 catalysts decrease as the order of 9%Ni-12%CeO₂/HZSM-5 > 9%Co-12%CeO₂/HZSM-5, 9%Mn-12%CeO₂/HZSM-5 > 9%Cu-12%CeO₂/HZSM-5, 9%Cr-12%CeO₂/HZSM-5 > 9%Fe-12%CeO₂/HZSM-5 > 12%CeO₂/HZSM-5. Large amounts of polychlorohydrocarbon such as C₂HCl₃ and C₂Cl₄ were generated over Ni, Co, Mn and Cu impregnated catalysts. Moreover, small concentration of C₂H₂Cl₄ was found when 9%Cu-12%CeO₂/HZSM-5 was used as the catalyst. The generation of polychlorohydrocarbon can cause secondary pollution. Among all the catalysts, 9%Cr-12%CeO₂/HZSM-5 not only displayed high activity for DCE destruction, but also produced the least polychlorohydrocarbons and showed high selectivity to CO₂ and HCl. The improved capability of dehydrochlorination and the deep oxidation of DCE were attributed to strong interactions between CrO_x and CeO₂, which prompted the migration of active oxygen species on 9%Cr-12%CeO₂/HZSM-5 surface.

• Key words：catalytic oxidation  volatile organic compounds(VOCs)  1,2-dichloroethane  ceria  transition metal oxides  HZSM-5 zeolite

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