[Electrochemical degradation of sodium pentachlorophenol on a Pd/C gas-diffusion electrode].
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) techniques. The electrochemical degradation of sodium pentachlorophenol (PCP-Na) 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 indicate that the two-electron reduction from O2 to hydrogen peroxide (H2O2) is produced at the Pd/C gas-diffusion electrode, and the accumulated H2O2 in the cathodic compartment reach to the steady concentration of 9.8 mg/L after 100 min. The Pd/C gas-diffusion cathode can reductively dechlorinate PCP-Na by feeding hydrogen gas, and 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-Na exceed 80% after 100 min, and the average removal efficiency of PCP-Na in terms of total organic carbon (TOC) exceeds 75% after 200 min by using Pd/C gas-diffusion cathode,which is better than that of the C/PTFE gas-diffusion cathode. High performance liquid chromatography (HPLC) allows identifying phenol as the dechlorination product.
Wang
Hui
H
College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China. wanghui616@gmail.com
Wang
Jian-Long
JL
D002244:Carbon / Q000737:chemistry; D002384:Catalysis; D004058:Diffusion; D004563:Electrochemistry; D004566:Electrodes; D010084:Oxidation-Reduction; D010165:Palladium / Q000737:chemistry*; D010416:Pentachlorophenol / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000379:methods*
D010165:Palladium; D002244:Carbon; D010416:Pentachlorophenol