物理化学学报 >> 2009, Vol. 25 >> Issue (06): 1190-1194.doi: 10.3866/PKU.WHXB20090625

研究论文 上一篇    下一篇

水溶液中2,4,6-三溴苯酚在银阴极上的选择性脱卤

朱英红, 徐颖华, 马昊, 赵峰鸣, 马淳安   

  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:2008-10-29 修回日期:2009-03-19 发布日期:2009-06-05
  • 通讯作者: 马淳安 E-mail:science@zjut.edu.cn

Selective Dehalogenation of 2,4,6-Tribromophenol in Aqueous Solution on a Silver Cathode

ZHU Ying-Hong, XU Ying-Hua, MA Hao, ZHAO Feng-Ming, MA Chun-An   

  1. State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, College of Chemical Engineering and Materials, Zhejiang University of Technology, Hangzhou 310032, P. R. China
  • Received:2008-10-29 Revised:2009-03-19 Published:2009-06-05
  • Contact: MA Chun-An E-mail:science@zjut.edu.cn

摘要:

采用循环伏安法比较了玻碳、光亮银和粗糙化银电极对2,4,6-三溴苯酚还原脱卤反应的电催化活性, 初步研究了碱性水溶液中2,4,6-三溴苯酚在粗糙化银电极上的还原脱卤历程; 在此基础上, 利用恒电位电解法进一步探索了2,4,6-三溴苯酚在粗糙化银电极上的电还原脱卤历程. 结果表明, 粗糙化银电极对2,4,6-三溴苯酚的选择性还原脱卤反应具有优良的电催化活性, 且其活性优于光亮银和玻碳电极; 2,4,6-三溴苯酚在粗糙化银电极上的还原反应是个逐步脱卤过程, 推测得出其邻位和对位C—Br键的还原断裂所需的活化能非常接近, 而反应中间产物2,4-二溴苯酚的对位C—Br键的还原断裂所需的活化能比邻位要低; 2,4,6-三溴苯酚能实现完全脱卤生成苯酚, 主要路径为2,4,6-三溴苯酚→2,4-二溴苯酚→2-溴苯酚→苯酚.

关键词: 选择性脱卤, 2,4,6-三溴苯酚, 银电极, 废水处理

Abstract:

The electrocatalytic activity of a roughened silver electrode towards the reductive dehalogenation of 2,4,6-tribromophenol was compared to a glassy carbon electrode and a polished silver electrode in basic aqueous solution by cyclic voltammetry (CV). Furthermore, the course of reductive dehalogention of 2,4,6-tribromophenol was studied by CV and controlled-potential electrolysis. Results indicated that roughened silver exhibited more powerful electrocatalytic activity than the glassy carbon electrode and the polished silver electrode for the selective dehalogention of 2,4,6-tribromophenol. The reduction of 2,4,6-tribromophenol was determined to be a stepwise dehalogenation as follows: 2,4,6-tribromophenol→2,4-dibromophenol→2-bromophenol→phenol. In addition, the activity energy needed for the dissociative reduction of the ortho carbon-halogen bond was similar to the para carbon-halogen bond for 2,4,6-tribromophenol and a higher energy was probably required for 2,4-dibromophenol to cleave the ortho carbon-halogen bond compared to the para carbon-halogen bond.

Key words: Selective dehalogenation, 2,4,6-tribromophenol, Silver electrode, Waste water treatment

MSC2000: 

  • O646