Abstract
The mechanisms of chlorine and oxygen electrochemical evolution at a novel Ti/SnO2-IrO2 anode were investigated using cyclic voltammetry and steady state current-potential measurements. For this study a laboratory constructed model cell was employed. Firstly, controlled potential electrolysis of 0.1 mol/L NaC1 was performed and chlorine was observed to evolve at potential +1.2V. The pH values of the solution decreased during electrolysis over the potential range of +1.0 V- +2.0 V, suggesting that oxygen evolution may involve in the reactions. Electrolysis with a de-oxygenated NaC1 solution at a fixed potential of +2.0 V confirmed that O2 is one of the products generated at the anode. Further electrolysis of NaC1 solution was conducted under steady state conditions. A potential-current density plot was constructed over the potential range of +1.00 V- +1.28 V. The slope of the plot at Tafel section was found to be 41 mV/ decade. These results indicate that chlorine evolution at the anode is achieved via an intermediate layer formed by electrosorption of oxygen and chlorine on the electrode surface.
* Supported by the Faculty of Applied Sciences, University of the West of England, Bristol, UK
Notes
* Supported by the Faculty of Applied Sciences, University of the West of England, Bristol, UK