The inhibitory effect of some surface active organic compounds on the electrooxidation of strongly adsorbed species derived from HCOOH on polycrystalline platinum

Abstract

The effect of dimethylsulphoxide (DMSO), acetonitrile (AN) and acetone (AC) on the adsorption and oxidation of formic acid on platinum electrodes was studied using radiometric and potentiodynamic methods. It was found that formic acid is not adsorbed on the electrode surface previously covered with DMSO, AN or AC. The oxidation of chemisorbed species derived from HCOOH in the presence of DMSO and AN is inhibited because of lowering of the surface concentration of adsorbed water which is an oxidant in the process. The catalytic effect of acetonitrile on the direct oxidation of formic acid on the platinum electrode was higher on smooth than on rough surfaces. The effect was not observed in the presence of DMSO and AC.