Adsorption and inhibitive properties of Tryptophan on low alloy steel corrosion in acidic media

作者：Abdel Fatah Hesham T M^*; Kamel Medhat M; Hassan Aliaa A M; Rashwan Salah A M; Abd El Wahaab Saad M; El Sehiety Hala E E

来源：Arabian Journal of Chemistry, 2017, 10: S1164-S1171.

DOI：10.1016/j.arabjc.2013.02.010

• Corrosion inhibition
• Acid cleaning
• Amino acids
• EIS
• EFM

The inhibition efficiency of Tryptophan (Trp) has been studied for the corrosion of low alloy steel ASTM A213 grade T22 in sulfamic (HSO3NH2) and hydrochloric (HCl) acid solutions.
Corrosion inhibition was studied using electrochemical methods (electrochemical impedance spectroscopy; EIS and the new technique electrochemical frequency modulation; EFM) and weight loss measurements. The influence of inhibitor concentration, solution temperature, and immersion time on the corrosion resistance of low alloy steel (LAS) has been investigated. Trp proved to be a very good inhibitor for low alloy steel acid corrosion. EFM measurements showed that Trp is a mixed type inhibitor. Trp behaved better in 0.6 M HCl than in 0.6 M HSO3NH2. Moreover, it was found that the inhibition efficiency increased with increasing inhibitor concentration, while a decrease was detected with the rise of temperature and immersion time. The associated activation energy (E-a) has been determined. The values of E-a indicate that the type of adsorption of Trp on the steel surface in both acids belongs to physical adsorption. The adsorption process was tested using Temkin adsorption isotherm.

• 出版日期2017-2