高等学校化学学报 ›› 2013, Vol. 34 ›› Issue (12): 2850.doi: 10.7503/cjcu20130326

• 物理化学 • 上一篇    下一篇

2,4-二氯苯酚的电化学氧化降解反应研究

马淳安, 王芬, 卢金金, 李美超, 郑万芳   

  1. 浙江工业大学化学工程与材料学院, 绿色化学合成技术国家重点实验室培育基地, 杭州 310032
  • 收稿日期:2013-04-11 出版日期:2013-12-10 发布日期:2013-06-13
  • 作者简介:李美超,女,博士,教授,博士生导师,主要从事光谱分析和电化学合成研究. E-mail:limc@zjut.edu.cn
  • 基金资助:

    国家“九七三”计划项目(批准号:2012CB722604);国家自然科学基金(批准号:21206147)和浙江省重点创新团队(批准号:2009R50002)资助.

Studies on Electrochemical Oxidation Reaction of 2,4-Dichlorophenol on Pt Electrode

MA Chun-An, WANG Fen, LU Jin-Jin, LI Mei-Chao, ZHENG Wan-Fang   

  1. College of Chemical Engineering and Materials Science, State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, Zhejiang University of Technology, Hangzhou 310032, China
  • Received:2013-04-11 Online:2013-12-10 Published:2013-06-13

摘要:

采用循环伏安法和原位红外光谱技术研究了2,4-二氯苯酚在Pt电极上的电化学氧化降解反应,结合Fukui函数值预测了2,4-二氯苯酚在电化学氧化过程中的反应位点. 结果表明,Pt电极对2,4-二氯苯酚有良好的电催化活性,2,4-二氯苯酚在电极表面反应主要有3个途径:直接通过电化学反应脱去氯离子,生成苯酚;在·OH的进攻下,C—Cl键断裂,4位Cl较2位Cl先脱去,生成苯二酚,并可进一步氧化生成苯醌以及不饱和羧酸;在·OH的进攻下发生苯环开环反应,生成含氯不饱和羧酸. 在1700 mV左右,2,4-二氯苯酚可经电化学氧化生成CO2.

关键词: 2,4-二氯苯酚, 电化学氧化, 原位红外光谱, Fukui函数

Abstract:

Cyclic voltammetry(CV) and in situ FTIR spectrometry were employed to study the electrochemical oxidation mechanism of 2,4-dichlorophenol(2,4-DCP) in NaOH solution. Density functional theory(DFT) was used to calculate the Fukui function for 2,4-DCP and gave the information on possible reactive sites of 2,4-DCP during electrochemical oxidation. CV results show that the Pt electrode exhibits a high electrochemical activity for the electrochemical oxidation reaction of 2,4-DCP. On the basis of in situ FTIR data, the electrochemical oxidation reaction of 2,4-DCP is as follows: (1) C—Cl band of 2,4-DCP is broken to form phenol directly; (2) C—Cl band of 2,4-DCP is broken and C—O band is formed with ·OH radicals, and the Fukui function results show that chlorine atom at 4 position is easier to be replaced with the hydrogen or ·OH radicals. Then hydroxylation reaction happens on the C4-position of phenol leading to form hydroquinone which is subsequently electrochemically oxidized to benzoquinone. With the potential increasing, aliphatic carboxylic acids are formed after the ring cleavage; (3) part of 2,4-DCP is electrochemically oxidized to chloromaleic acid directly. At about 1700 mV, CO2 could be formed during electrochemical oxidation reaction of 2,4-DCP on Pt electrode.

Key words: 2,4-Dichlorophenol, Electrochemical oxidation, In situ FTIR spectrum, Fukui function

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