The synergistic effect of quaternary ammonium cations on the corrosion inhibition of Fe by inorganic anions

The synergistic effect of tetrabutylammonium cation (TBA⁺) or N-hexadecylpyridinium cation (HDP⁺) and SCN⁻ or I⁻ in 0.5 mol·L⁻¹ H₂SO₄ solution on the corrosion inhibition of Armco iron was investigated by potentiodynamic polarization and polarization resistance measurements. The results show that the synergistic effect of HDP⁺ containing π-electron and anion is stronger than that of TBA⁺ and anion. The joint adsorption models of cation and anion at electrode-solution interface are related to the structure and property of both ions by analyzing the desorption behaviours of both ions when the electrode is polarized anodically. Supported by the national scientific foundation of China Zou Jinyun: born in Aug. 1936. Prof.