Electrooxidation of linear alkyl benzene sulfonate (LAS) on Pt electrodes

The electrochemical behaviour of linear alklybenzene sulfonate (LAS) on Pt electrodes was investigated in 0.05M Na2SO4 and in 0.1M NaCl at pH=8 by the potentiokinetic method and by electrolysis. The anodic and cathodic semilo garithmic current-potential curves were obtained between -1.6V - +1.6V. The experimental discharge potentials were determined by means of current-pote ntial-curves obtained by electrolysis between 0-3V. The percentages of surf ace active material remaining in the solution after specified periods (0-6h rs) were determined for different initial concentrations of LAS (30, 150, 3 00 ppm) by using a potentiostat at +1.6V and by applying a potential of 20V via a direct current source. The concentrations of LAS in the solution wer e determined with a UV spectrophotometer. The results indicate that when a potential of 20V is applied on the electrodes the concentrations of surface active materials (LAS) decrease by 40-50% at the end of 6 hours in 0.05M N a2SO4 solution.