Chlorobenzene degradation by electro-heterogeneous catalysis in aqueous solution: intermediates and reaction mechanism.
This study was performed to investigate the variables that influence chlorobenzene (CB) degradation in aqueous solution by electro-heterogeneous catalysis. The effects of current density, pH, and electrolyte concentration on CB degradation were determined. The degradation efficiency of CB was almost 100% with an initial CB concentration of 50 mg/L, current density 15 mA/cm2, initial pH 10, electrolyte concentration 0.1 mol/L, and temperature 25 degrees C after 90 min of reaction. Under the same conditions, the degradation efficiency of CB was only 51% by electrochemical (EC) process, which showed that electro-heterogeneous catalysis was more efficient than EC alone. The analysis results of Purge-and-Trap chromatography-mass spectrometry (P&T/GC/MS) and ion chromatography (IC) indicated that in the reaction process, the initial *OH attack could occur at the C-Cl bond of CB, yielding phenol and biphenyl with the release of Cl-. Further oxidation of phenol and biphenyl produced p-Vinylbenzoic acid and hydroquinol. Finally, the compounds were oxidized to butenedioic acid and other small-molecule acids.
Wang
Jiade
J
College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310032, China. jdwang@zjut.edu.cn
Mei
Yu
Y
Liu
Chenliang
C
Chen
Jianmeng
J
D002244:Carbon / Q000302:isolation & purification; D002384:Catalysis; D002722:Chlorobenzenes / Q000737:chemistry*; D004560:Electricity; D004563:Electrochemistry / Q000379:methods*; D004573:Electrolytes / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry; D006863:Hydrogen-Ion Concentration; D008855:Microscopy, Electron, Scanning; D012996:Solutions
D002722:Chlorobenzenes; D004573:Electrolytes; D012996:Solutions; D002244:Carbon; C031294:chlorobenzene