化学学报 ›› 2009, Vol. 67 ›› Issue (8): 746-750. 上一篇    下一篇

研究论文

原位红外光谱法研究对氯苯酚在Pt电极上的电氧化行为

马淳安* 刘艳娜 李美超

  

  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)

  • 投稿日期:2008-09-14 修回日期:2008-12-16 发布日期:2009-04-28
  • 通讯作者: 马淳安

In-situ FTIR Studies on Electrooxidation of p-Chlorophenol on Pt Electrode

Ma, Chunan* Liu, Yanna Li, Meichao   

  1. (College of Chemical Engineering and Materials Science, State Key Laboratory Breeding Base of Green Chemistry-synthesis Technology, Zhejiang University of Technology, Hangzhou 310032)
  • Received:2008-09-14 Revised:2008-12-16 Published:2009-04-28
  • Contact: Ma, Chunan

采用原位红外光谱法研究了碱性条件下对氯苯酚(PCP)在Pt电极上电化学氧化的脱氯反应机理. 研究结果表明Pt电极对PCP有良好的电化学反应活性, 其氧化过程首先是对氯苯酚负离子氧化生成对氯苯氧自由基, 该自由基可与对氯苯酚负离子作用生成芳香醚低聚物; 随着电位升高, 对氯苯酚负离子经电化学氧化生成了苯二酚盐(还可能存在其氧化产物不饱和羧酸盐); 当电位继续升高, 苯二酚盐进一步氧化形成苯醌; 最后, 在Pt表面生成小分子羧酸盐, 同时生成了最终产物CO2. 但由于芳香醚低聚物等不溶性聚合物膜的形成并吸附在Pt电极表面, 可造成Pt电极毒化, 使得Pt电极在使用过程中逐渐失去活性.

关键词: 原位红外光谱法, Pt电极, 对氯苯酚, 电氧化

Electrochemical oxidation of p-chlorophenol (PCP) on a Pt electrode in alkaline solution has been investigated using in situ FTIR technique. Results showed that the Pt electrode exhibited a good performance for the electrooxidation of PCP. Firstly, p-chlorophenol anion on the surface of Pt electrode was electrooxidized to p-chlorophenolic radical, which reacted with p-chlorophenol anion to generate insoluble aromatic ether oligomer. With the increase of potential, p-chlorophenol anion was transformed to dihydroxybenzene (maybe with unsaturated carboxylic acids). Then, the dihydroxybenzene could be electrooxidized to benzoquinone at more positive potential. Finally some light weight carboxylate and ultimate product CO2 were achieved. But the Pt electrode could be poisoned with formation of the insoluble oligomer on its surface, and may lose its electrochemical activity gradually.

Key words: in situ FTIR, Pt electrode, p-chlorophenol, electrooxidation