Electrochemical Studies of Inhibition of Zinc Corrosion in Hydrochloric Acid by Phosphonium Salts

The performance of five synthesised phosphonium salts, 4-tolyltriphenyl-phosphonium chloride (TTPPC), 4-phenoltriphenylphosphonium chloride (PTPPC), 4-anilinetriphenylphosphonium bromide (ATPPB), 4-benzyl alcoholtriphenylphosphonium chloride (BATPPC), 4-chlorophenyltriphenylphosphonium bromide (CPTPPB) and two commercially available phosphonium salts, tetraphenylphosphonium bromide (TPPB), and methyltriphenylphosphonium bromide (MTPPB) for the inhibition of zinc corrosion in 1 M HCl at 22°C has been quantified using electrochemical techniques. The inhibitor concentration ranged from 1 × 10–3 to 1 × 10–7 mol dm–3. The degree of corrosion inhibition for zinc in 1 M HCl at 22°C was found to be in the order: CPTPPB > TTPPC > TPPB > PTPPC > BATPPC > MTPPB > ATPPB.