Cathodic Reactions on an Iron RDE in the Presence of Y(III)

Abstract

During electrolysis of a solution containing ions, a hydrous film forms in the alkaline layer close to a hydrogen-evolving cathode. The film hinders the reduction of dissolved oxygen and activates the reduction of water, hydrogen evolution. The ability to hinder certain reactions while catalyzing hydrogen evolution may be useful in electrolysis applications. In this work the electrochemical properties of an in situ formed yttrium-hydroxide film were studied on an iron rotating disk electrode (RDE) in with addition of , , and of . It was found that the film also hinders the reduction of protons, hypochlorite ions, and nitrate ions. At low concentration of or at high current density, when the hydrogen evolution was vigorous, no activation of hydrogen evolution was observed. Under these conditions the film still hindered the reduction of ions. The reactant in the catalyzed hydrogen evolution reaction is most likely water molecules within the hydrous film. Nitrate ions were easily reduced on an iron cathode when no ions were present in the solution. When studying effects of yttrium addition to a chloride solution the use of , rather than , as source is recommended.