Solvent and support electrolyte effects on the catalytic activity of Ti/RuO2 and Ti/IrO2 electrodes: oxidation of isosafrole as a probe model

The electrocatalytic behavior of Ti/RuO2 and Ti/IrO2 electrodes was investi gated as function of the supporting electrolyte and solvent. A decrease was observed in the electrochemically active area of the electrode as the cati on size increases. The oxidation potential of a series of organic solvents tested showed a straight relationship with Gutmann's donor number: the high er the GDN the more easily is the solvent oxidized. Oxidation of isosafrole , ISF, was used as a probe reaction to examine the influence of the support ing electrolyte cation size and the composition of the organic solvents on the electrocatalytic activity of the electrodes. The global catalytic activ ity for ISF oxidation is independent of the size of the supporting electrol yte cation and of the electrode material. For both electrode materials inve stigated it was verified that the following sequence holds for the influenc e of the solvent on the overall catalytic efficiency of ISF oxidation: AN > PC > DMSO approximate to DMF, (C) 1999 Elsevier Science Ltd. All rights re served.