The anodic dissolution of palladium in deoxygenated acidic chloride solutions has been studied and the reaction order determined. Two reaction mechanisms are proposed, as functions of the pH value. At lower pH, the effect of chloride ion on electro-dissolution kinetics increases as the hydrogen ion concentration increases. In a critical pH region, the adsorption of OH** minus competes with Cl** minus resulting in the formation of PdOH//a//d which then inhibits the corrosion process. 8 Refs.