催化学报

催化学报 ›› 2012, Vol. 33 ›› Issue (3): 557-562.DOI: 10.3724/SP.J.1088.2012.11003

• 研究论文 • 上一篇    下一篇

CeO2-MnOx 催化剂上氯乙烯有机废气的催化燃烧

万义玲1,2, 张传辉2, 郭杨龙2,*, 郭耘2, 卢冠忠2   

  1. 1广东海洋大学理学院, 广东湛江 524088; 2华东理工大学工业催化研究所, 上海 200237
  • 收稿日期:2011-10-05 修回日期:2011-11-15 出版日期:2012-03-15 发布日期:2015-07-27

Catalytic Combustion of Vinyl Chloride Emission over CeO2-MnOx Catalyst

WAN Yiling1,2, ZHANG Chuanhui2, GUO Yanglong2,*, GUO Yun2, LU Guanzhong2   

  1. 1College of Science, Guangdong Ocean University, Zhanjiang 524088, Guangdong, China; 2Research Institute of Industrial Catalysis, East China University of Science and Technology, Shanghai 200237, China
  • Received:2011-10-05 Revised:2011-11-15 Online:2012-03-15 Published:2015-07-27

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摘要： 采用柠檬酸 (CA) 溶胶-凝胶法制备了不同 Mn:(Ce+Mn) 摩尔比的CeO2-MnOx 催化剂, 以氯乙烯有机废气的催化燃烧为模型反应, 考察了催化剂制备条件和反应条件对于 CeO2-MnOx 催化剂性能的影响, 并用 N2 吸附、X 射线衍射 (XRD) 和 H2 程序升温还原 (H2-TPR) 对催化剂进行了表征. 结果表明, CeO2-MnOx 催化剂上氯乙烯燃烧反应产物只有 HCl, H2O 和 CO2, 没有检测到其他氯代烃和氯气等副产物. 当 CA:Mn:Ce = 0.3:0.50:0.50 时, 所制备的 CeO2-MnOx 催化剂活性最高, 对于较宽的空速范围 (10000~30000 h-1) 和较宽的浓度范围 (0.05%~0.15%), 低浓度氯乙烯的催化燃烧反应具有较好的操作弹性. 其中当氯乙烯浓度为 0.1%, 空速为 15000 h-1时, 起燃温度 T50 = 110 oC, 完全转化温度 T99 = 220 oC. XRD 和 H2-TPR 结果表明, 在 CeO2-MnOx 催化剂中只出现立方相萤石结构 CeO2 的特征衍射峰, 没有出现 MnOx 物种的特征衍射峰; Mn 离子进入 CeO2 晶格形成的 Ce-Mn-O 固溶体, 有利于提高催化剂表面的活性氧物种的活性, 乃至催化剂活性.

关键词: 铈, 锰, 复合氧化物, 氯乙烯, 催化燃烧, 固溶体, 氧物种

Abstract: CeO2-MnOx catalyst samples with different Mn/(Ce+Mn) molar ratios (0, 1/4, 1/2, 3/4, and 1) prepared by the citric acid (CA) sol-gel method were studied for catalytic combustion of vinyl chloride (VC) emission. The effects of preparation conditions and operation parameters on the catalytic performance of CeO2-MnOx were investigated. The catalyst samples were characterized by N2 adsorption, X-ray diffraction (XRD), and H2 temperature-programmed reduction (H2-TPR). In the catalytic combustion of VC over CeO2-MnOx, the products containing HCl, CO2, and H2O were produced and there were no byproducts such as chlorohydrocarbons and chlorine. The CeO2-MnOx catalyst with the molar ratio of CA:Mn:Ce = 0.30:0.50:0.50 showed the best catalytic performance and had better operating flexibility over the ranges of gas hourly space velocity (GHSV) of 10000–30000 h-1 and VC concentration of 0.05%–0.15%. The temperatures at 50% conversion (110 oC) and at 99% conversion (220 oC) were achieved at VC concentration of 0.1% and GHSV of 15000 h-1. XRD characterization indicated that only the characteristic diffraction peaks of CeO2 with the cubic fluorite structure appeared and no characteristic diffraction peaks of MnOx species appeared over CeO2-MnOx catalyst. XRD and H2-TPR results indicated that Mn ions were incorporated into the CeO2 lattice to form Ce-Mn-O solid solution, which was favorable for improving the reactivity of active oxygen species on the catalyst surface and thereby enhanced the catalyst activity.

Key words: cerium, manganese, composite oxide, vinyl chloride, catalytic combustion, solid solution, oxygen species