物理化学学报 >> 2001, Vol. 17 >> Issue (03): 278-281.doi: 10.3866/PKU.WHXB20010320

研究论文 上一篇    下一篇

甲醛光催化氧化的反应机理

杨建军;李东旭;李庆霖;张治军;汪汉卿   

  1. 中国科学院兰州化学物理研究所,兰州　730000;河南大学润滑与功能材料实验室,开封　475001
  • 收稿日期:2000-10-08 修回日期:2000-11-21 发布日期:2001-03-15
  • 通讯作者: 李庆霖 E-mail:qlli01@371.net

Mechnism of Photocatalytic Oxidation of Formaldehyde

Yang Jian-Jun;Li Dong-Xu;Li Qing-Lin;Zhang Zhi-Jun;Wang Han-Qing   

  1. Lanzhou Institute of Chemical Physics,Chinese Academy of Science,Lanzhou　730000;Key Lab of Lubrication and Functional Materials,Henan University,Kaifeng　475001
  • Received:2000-10-08 Revised:2000-11-21 Published:2001-03-15
  • Contact: Li Qing-Lin E-mail:qlli01@371.net

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摘要： 采用程序升温脱附（TPD）, 电子自旋共振（ESR）及自旋捕获电子自旋共振(ST  ESR)等物理方法对甲醛光催化氧化过程中,反应物的吸附状态、自由基中间物种及反应机理 进行了研究.结果表明,在光催化氧化空气中微量甲醛的反应条件下,吸附在催化剂表面的空 气中的氧气被光生电子还原为•O－2,微量水被空穴氧化为•OH.二者为甲醛的深度氧化提供了高活性的氧化剂.甲醛是通过中间产物甲酸而氧化为终点 产物二氧化碳的.

关键词: 甲醛, 光催化氧化, 程序升温脱附, 电子自旋共振

Abstract: The adsorption state of reactants,free radical intermediates and the r eaction mechanism have been studied by means of temperature programmed descripti on (TPD),electron spin resonance (ESR) and spin trapingESR in the photocatalyt ic oxidation of formaldehyde.The results showed that O2 adsorbed on the surface of photocatalyst could be reduced to •O－2 by photogenerated electrons and H2O could be oxidized to •OH by holes.Both free radicals are active oxidants in the reaction of photocatalytic oxidation of HCHO.The photocatalytic oxidation of HC HO carried out with two steps.Firstly,HCHO was oxidized into HCOOH,then HCOOH co nverted into final product of CO2 and H2O.

Key words: Formaldehyde, Photocatalytic oxidation, Temperature programmed deso rption, Electron spin resonance