Electrochemical degradation of pentachlorophenol using a palladium modified gas-diffusion electrode

摘要

Pd/C catalyst was prepared by hydrogen reduction method and used for the Pd/C gas-diffusion electrode.It was characterized by cyclic voltammetry(CV)technique.The electrochemical degradation of pentachlorophenol(PCP)was investigated in a diaphragm electrolysis device,feeding firstly with hydrogen gas then with air using the Pd/C gas-diffusion electrode and the carbon/polytetrafluoroethylene (C/PTFE)gas-diffusion electrode as the cathode,respectively.The results indicated that the Pd,C gas-diffusion cathode can not only reducfively dechlorinate PCP by feeding hydrogen gas.but also accelerate the two-electron reduction of O2 to hydrogen peroxide(H2O2)by feeding air.Therefore,both the removal efficiency and the dechlorination degree of PCP exceeded 80％after 120 min.and the average removal efficiency of PCP in terms of total organic carbon(TOCl exceeds 75％after 200 min by using Pd/C gas-diflusion cathode.which was better than that of the C,PTFE gas-diffusion cathode.High-performance liquid chromatography(HPLC)allows identifying phenol as the dechlorination product.