催化学报

催化学报 ›› 2006, Vol. 27 ›› Issue (12): 1073-1079.

• 研究论文 • 上一篇    下一篇

催化湿式氧化苯酚的TiO2-CeO2催化剂的制备与表征

陈正雄,祝万鹏,杨少霞,王建兵   

  1. 清华大学环境科学与工程系, 北京 100084
  • 收稿日期:2006-12-25 出版日期:2006-12-25 发布日期:2006-12-25

Preparation and Characterization of TiO2-CeO2 Catalyst for Catalytic Wet Air Oxidation of Phenol

CHEN Zhengxiong, ZHU Wanpeng*, YANG Shaoxia, WANG Jianbing   

  1. Department of Environmental Science and Engineering, Tsinghua University, Beijing 100084, China
  • Received:2006-12-25 Online:2006-12-25 Published:2006-12-25

PDF

854

被引次数

19

摘要： 采用共沉淀法制备了催化湿式氧化降解苯酚的TiO2-CeO2催化剂,通过单因素多次实验和正交实验两种不同的实验方式,考察了不同的制备条件如活性组分配比、焙烧温度、焙烧时间和老化过程的pH值等对催化剂活性的影响,证明了老化过程中保持较高pH值对于TiO2-CeO2催化剂的活性具有决定性作用. 当活性组分摩尔配比为1:1, 焙烧温度为450 ℃, 焙烧时间为5.0 h, 老化过程中pH保持为11时得到的催化剂,在反应温度为150 ℃, 氧分压为4.5 MPa的条件下,经90 min的反应,浓度为2.1 g/L的苯酚溶液COD去除率达到了93%. 通过热重差热、N2吸附-脱附、 X射线衍射(XRD)和X射线光电子能谱(XPS)等分析方法揭示了催化剂的微观结构. 结果表明, BET比表面积、表面吸附氧以及表面三价金属元素的相对含量等物理和化学结构特性对催化剂的活性有重要影响.

关键词: 氧化钛, 氧化铈, 复合氧化物催化剂, 催化湿式氧化, 苯酚

Abstract: TiO2-CeO2 catalysts for catalytic wet air oxidation of phenol were prepared by coprecipitation. Effects of proportion of active components, calcination temperature, calcination time, and pH value during the aging process on the catalyst activity were investigated. The results indicated that keeping a constant pH of 11 during the aging was crucial for the catalytic activity of TiO2-CeO2. The microstructure of the catalysts was characterized by thermogravimetry-differential thermal analysis, N2 adsorption-desorption, X-ray diffraction, and X-ray photoelectron spectroscopy. The physical and chemical properties, such as BET specific surface area, chemisorbed oxygen, and relative content of Ce(Ⅲ) or Ti(Ⅲ) on the surface of TiO2-CeO2, had significant influence on the catalytic activity of the TiO2-CeO2 catalysts.

Key words: titanium dioxide, cerium dioxide, complex oxide catalyst, catalytic wet air oxidation, phenol