REDUCTION OF PERCHLORATE ION ON RUTHENIUM ELECTRODES IN AQUEOUS-SOLUTIONS

During slow potential scanning (less than 10 mv/s) of the hydrogen region at electrodeposited ruthenium electrodes (Ru/Pt) in HClO//4 solutions at room temperature, a rapid change from anodic to cathodic current is recorded following the peak of oxidation of adsorbed hydrogen. The maximum of this current reversal appears at potentials around 120 mv (SHE). The negative sweep of the voltammogram exhibits a current peak that corresponds to reduction of adsorbed oxygen. Addition of H//2SO//4 or HCl to HClO//4 solutions proves that the current reversal is due to the presence of perchlorate ions. The results suggest that perchlorate reduction proceeds through interaction of the anion and hydrogen adsorbed on the Ru electrode to the final products of Cl** minus and H//2O.