Contribution of cathodic hydroxyl radical generation to the enhancement of electro-oxidation process for water decontamination
The degradation of organic pollutants in water by electro-oxidation (EO) process is a very active research topic, but it has been pre-eminently focused on the development of anodes with enhanced electrocatalytic ability to produce ●OH at their surface. Conversely, the degradation pathways that may a...
| Autores: | , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión aceptada para publicación |
| Fecha de publicación: | 2019 |
| País: | España |
| Institución: | Universidad de Barcelona |
| Repositorio: | Dipòsit Digital de la UB |
| OAI Identifier: | oai:diposit.ub.edu:2445/153081 |
| Acceso en línea: | https://hdl.handle.net/2445/153081 |
| Access Level: | acceso abierto |
| Palabra clave: | Depuració d'aigües residuals Oxidació electroquímica Purification of sewage Electrolytic oxidation |
| Sumario: | The degradation of organic pollutants in water by electro-oxidation (EO) process is a very active research topic, but it has been pre-eminently focused on the development of anodes with enhanced electrocatalytic ability to produce ●OH at their surface. Conversely, the degradation pathways that may arise from the potential ●OH production at the cathode surface are often disregarded. This work discusses the contribution of ●OH, formed at a Ti, graphite, stainless steel or Pt cathode from the reduction of O2 or H2O2, to phenol oxidation in 0.5 mol dm-3 H2SO4 medium. The OH production in the cathodic compartment of a divided cell was assessed from coumarin oxidation monitored via UV/Vis spectroscopy and HPLC with a fluorescence detector, salicylic acid oxidation evaluated by HPLC with a photodiode array detector and electron paramagnetic resonance. It was demonstrated that the production depended on the cathode nature, decreasing as: Pt > graphite >> stainless steel > Ti. It was concluded that a two-electron reaction converted O2 to H2O2, which was monoelectronically reduced to ●OH. The results reveal the importance of cathode selection in water treatment by EO. |
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