Polycrystalline platinum rotating disc electrode study of the liquid system 0.2 M LiClO<inf>4</inf> -H<inf>2</inf>O-DMSO in nitrogen and oxygen atmosphere

Abstract

The electrochemical reactions in the system dimethylsulphoxide (DMSO)-water with 0. M LiClO4 added as the supporting electrolyte, saturated either by nitrogen or by oxygen, were investigated by voltammetry on polycrystalline platinum rotating disc electrode. In the water-rich composition region, the reduction of decomposition voltage was observed, which was attributed to the suppression of inhibiting effect of platinum oxide on oxygen evolution reaction. By comparing experimentally determined limiting current density of oxygen reduction reaction to the one calculated by means of Levich equation, it was confirmed that the 4e- path holds in the DMSO mole fraction region between 0 and 70 mol.%, while in the DMSO-rich region, combined effect of both the depression of reaction path toward to 1e- one, and the electrode passivation by lithium compounds, became effective. © 2013 by ESG.