Specific effects of propargyl alcohol and propargyl chloride on an iron electrode in inorganic acids

The effect of acetylenic compounds, namely, propargyl alcohol (PA) and propargyl chloride (PC), on electrode processes occurring on Armco iron in hydrochloric, sulfuric, phosphoric, and perchloric acids was studied with the use of potentiostatic polarization. In oxygen-containing acids with hydrophilic anions, PA and PC are hydrogenated, thus decreasing the cathodic overpotential and significantly retarding iron ionization, which causes pitting at a free corrosion potential. More hydrophobic Cl− anions increase the cathodic overpotential and hinder the hydrogenation process. Propargyl chloride inhibits electrode reactions and iron corrosion more effectively than does less hydrophobic PA.