催化学报

催化学报 ›› 2011, Vol. 32 ›› Issue (6): 904-916.DOI: 10.1016/S1872-2067(10)60216-1

• 研究论文 • 上一篇    下一篇

常温下 MnO2/Al2O3 催化剂催化臭氧氧化甲苯反应

龙丽萍 1,2, 赵建国 1,2, 杨利娴 1,2, 付名利 1,2, 吴军良 1,2, 黄碧纯 1,2, 叶代启 1,2,*   

  1. 1 华南理工大学环境科学与工程学院, 广东广州 510006; 2 华南理工大学工业聚集区污染控制与生态修复教育部重点实验室, 广东广州 510006
  • 收稿日期:2010-11-19 修回日期:2011-01-23 出版日期:2011-06-21 发布日期:2014-10-31

Room Temperature Catalytic Ozonation of Toluene over MnO2/Al2O3

LONG Liping1, ZHAO Jianguo1,2, YANG Lixian1,2, FU Mingli1,2, WU Junliang1,2, HUANG Bichun1,2, YE Daiqi1,2,*   

  1. 1College of Environmental Science and Engineering, South China University of Technology, Guangzhou 510006, Guangdong, China; 2Key Laboratory of Ministry of Education for Pollution Control and Ecosystem Restoration in Industry Clusters, South China University of Technology, Guangzhou 510006, Guangdong, China
  • Received:2010-11-19 Revised:2011-01-23 Online:2011-06-21 Published:2014-10-31

PDF

1944

摘要： 采用浸渍法制备了 Al2O3 负载的 5 种过渡金属氧化物催化剂, 考察了它们在常温下催化臭氧氧化甲苯的性能, 并运用程序升温还原、程序升温氧化、N2 吸附-脱附和 X 射线光电子能谱对催化剂进行了表征. 结果表明, NiO/Al2O3, CoO/Al2O3 和 MnO2/Al2O3 催化剂上活性氧中心数量较少, 臭氧与甲苯转化率较高; 而 Fe2O3/Al2O3 和 CuO/Al2O3 催化剂上则相反. 催化降解臭氧效率较高的催化剂上甲苯转化率也较高, 在本文实验条件下, CO2 产率低于 30%. 当甲苯浓度为 666 mg/m3, O3 浓度从 193 mg/m3 提高至 965 mg/m3 时, 甲苯转化率从 15.2% 提高至 46.7%, 并且使反应后催化剂表面产物和晶格氧含量增加. 原位漫反射红外光谱研究发现, 反应过程中生成了含 COO?, C=O 和 C–O 官能团的物质, O3 浓度的提高加速了 COO?向 C=O 与 C–O 的转化, 前者在 573 K O2 气氛下几乎不发生反应, 而后者在 373 K 开始分解. 基于此, 提出了常温下臭氧催化氧化甲苯的反应机理.

关键词: 三氧化二铝, 过渡金属氧化物, 甲苯, 臭氧, 室温, 原位漫反射红外光谱

Abstract: Five kinds of transition metal oxides supported on alumina and prepared by wetness impregnation were evaluated for the catalytic ozonation of toluene at room temperature and characterized by temperature-programmed reduction, temperature-programmed oxidation, N2 adsorption-desorption, and X-ray photoelectron spectroscopy. The catalysts with a lower reduction temperature and less H2 consumption showed a higher efficiency for ozone and toluene decomposition, such as NiO/Al2O3, CoO/Al2O3, and MnO2/Al2O3, while lower efficiency were observed on Fe2O3/Al2O3 and CuO/Al2O3. Toluene decomposition efficiency was obviously dependent on ozone. Because of the low ozone to toluene concentration ratio, a CO2 yield of less than 30% was obtained. At a toluene concentration of 666 mg/m3 and an ozone concentration between 193 and 965 mg/m3, toluene conversion was found to vary from 15.2% to 46.7%. Additionally, we observed an increase in oxidation products and lattice oxygen on the catalyst surface. A preliminary investigation into the reaction pathway was undertook by in situ diffuse reflectance Fourier transform infrared spectroscopy. With regards to the formation of COO-, C=O, and C–O groups the high ozone concentration accelerated the transformation from COO- to C=O and C–O. The substance containing COO- remained unchanged at 573 K, while the substances containing C=O and C–O underwent oxidation at higher than 373 K. A possible reaction pathway is proposed based on these findings.

Key words: alumina, transition metal oxide, toluene, ozone, room temperature, in situ diffuse reflectance Fourier transform infrared spectroscopy