Open AccessInvestigation of Corrosion Protection of Austenitic Stainless Steel in 5.5 M Polluted Phosphoric Acid Using 5-Azidomethyl-7-morpholinomethyl-8-hydroxyquinoline as an Ecofriendly Inhibitor
Author(s) -
Aimad Mazkour,
Souad El Hajjaji,
Najoua Labjar,
El Mostapha Lotfi,
Mohammed El Mahi
Publication year - 2021
Publication title -
international journal of corrosion
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.312
H-Index - 18
eISSN - 1687-9333
pISSN - 1687-9325
DOI - 10.1155/2021/6666811
Subject(s) - phosphoric acid , adsorption , corrosion , langmuir adsorption model , corrosion inhibitor , dielectric spectroscopy , langmuir , nuclear chemistry , materials science , polarization (electrochemistry) , dissolution , chemistry , inorganic chemistry , metallurgy , organic chemistry , electrochemistry , electrode
The use of 5-azidomethyl-7-morpholinomethyl-8-hydroxyquinoline (AMH) as a corrosion inhibitor for AISI 321 stainless steel in 5.5 M polluted phosphoric acid was investigated using the hydrogen evolution technique, linear polarization curves, and impedance spectroscopy. Impedance measurements revealed that the dissolution of AISI 321 in 5.5 M polluted phosphoric acid was controlled by an activation mechanism, unchanged even with the addition of AMH at different concentrations. Polarization results showed that the inhibition ability was enhanced with increasing inhibitor concentration. AMH acted as a mixed-type inhibitor by random adsorption on the alloy surface, whatever the nature of the reaction that is taking place. The adsorption of AMH on the AISI 321 surface was also discussed via the Langmuir adsorption isotherm. The influence of elevating the solution temperature on the corrosion inhibition performance was studied. A quantum chemistry study with the DFT method was also conducted, which supplied a logical and exploitable theoretical explanation of the adsorption and the inhibition action of AMH on AISI 321.