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Assessment of Corrosion Inhibition Performance and Adsorption Thermodynamics of Hydrogen Phosphate (HPO 4 2− ) and Molybdate (MoO 4 2− ) Oxyanions on Tin in Maleic Acid
Author(s) -
Ait Addi Brahim,
El Ibrahimi Brahim,
Ait Addi Abdelaziz,
Shaban Abdul,
Ait Addi ElHabib,
Hamdani Mohamed
Publication year - 2021
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.202060581
Subject(s) - tin , molybdate , inorganic chemistry , adsorption , chemistry , electrochemistry , corrosion , dielectric spectroscopy , polarization (electrochemistry) , analytical chemistry (journal) , organic chemistry , electrode
The influence of hydrogen phosphate (HPO 4 2− ) and molybdate ions (MoO 4 2− ) on the behavior of tin corrosion in 0.2 M maleic acid was compared using experimental and theoretical techniques. The experimental studies consisted of the electrochemical investigations (potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS)), along with the surface analytical techniques (SEM and EDX). Additionally, the theoretical analysis (the chemical quantum computations at MP4/SDD level of theory in the aqueous phase), was conducted. The experimental outcomes illustrated that the inhibition efficiency (η%) increases with the concentration of the inhibitors, reaching 88 % and 81 % at 2×10 −2 M concentration of MoO 4 2− and HPO 4 2− , respectively. The potentiodynamic polarization curves revealed that HPO 4 2− performance is a cathodic‐type inhibitor, while MoO 4 2− shows a mixed‐type behavior. The increase in temperature decreased the η% values of both inhibitors. Based on surface analysis and thermodynamic study, the presence of the two inhibitors formed protective films on the tin surface through a physisorption mechanism. The chemical quantum computations using the complete fourth‐order Møller Plesset perturbation theory (MP4 with SDD basis) method results outlined the favorable affinity of the investigated inorganic inhibitors to interact with the tin surface, which interprets the well‐observed inhibition efficiencies.