The Effect of Acetylenic Molecules on Cathodic Overvoltage on Steel in Acid Solutions

Abstract

An apparatus was constructed for measuring changes in electrode potential at constant current density. Large increases in hydrogen overvoltage were noted when acetylenic molecules were adsorbed on a steel cathode, and cathodic reduction of dissolved oxygen was apparently inhibited. The effect on the anodic oxidation of steel was small. Thus, it can be concluded that these molecules slow down the oxidation of steel in acid solutions by inhibiting the cathodic reactions. The most effective adsorbates are characterized by steric availability of the acetylenic bond, non‐ionic character, and large molecular size.