Peptidic compound as corrosion inhibitor for brass in nitric acid solution

Abstract The study of Boc–Phe–Met–OCH 3 as corrosion inhibitor for 60Cu–40Zn in nitric acid solution was performed through weight loss and electrochemical polarisation measurements. The corrosion rate is highly reduced in the inhibited nitric acid. The inhibition efficiency E (%) reached a maximum value of 100% for Boc–Phe–Met–OCH 3 . Polarisation measurements indicated that Boc–Phe–Met–OCH 3 acted as cathodic inhibitors without changing the mechanism of the hydrogen evolution reaction. The results showed that the inhibition occurred via chemisorption of the inhibitor molecules on the corroding metal following Frumkin’s isotherm. The effect of the temperature in the range 303–353 K on the corrosion of Cu–Zn alloy in 0.5 M nitric acid with and without addition of Boc–Phe–Met–OCH 3 has been studied. The associated activation energy has been determined.