Electrochemical and theoretical studies of the interactions of a pyridyl-based corrosion inhibitor with iron clusters (Fe15, Fe30, Fe45, and Fe60).
Julian Cruz-BorbollaEsteban Garcia-OchoaJayanthi NarayananPablo Maldonado-RivasThangarasu PandiyanJosé M Vásquez-PérezPublished in: Journal of molecular modeling (2017)
The capacity of 2,6-bis[((2-pyridylmethyl)oxy)methyl)]pyridine (BPMMP) to inhibit the corrosion of mild carbon steel in HCl was analyzed. In a polarization study, both the cathodic and anodic currents were appreciably decreased in the presence of BPMMP, suggesting that this ligand is effective at inhibiting corrosion at the metal surface. This conclusion is consistent with the results of impedance analysis, where only one time constant corresponding to one depressed capacitive loop was detected, and the diameter of the impedance plot was directly related to the concentration of BPMMP. Furthermore, when recurrence analysis was performed, a decrease in regular noise was observed due to the change of Shannon entropy when the inhibitor was present in the corrosive medium, showing that a high degree of recurrence increases the entropy of the system. Electrochemical data on some pyridyl-based inhibitors were collected from the literature and used to plot (i) I corr (A/cm2) vs. inhibition efficiency (η%) and (ii) ΔG°ads vs. inhibition efficiency (ƞ%) in order to examine the general relationships between these parameters. Furthermore, the interactions of the ligand BPMMP with different iron clusters (Fe15, Fe30, Fe45, and Fe60) were analyzed theoretically using density functional theory (DFT). The structural and electronic properties of BPMMP and its protonated form BPMMPH+ were studied before and after the interactions of BPMMP with the iron clusters. The first protonation was found to occur at pyridine nitrogen atom N1, resulting in a Gibbs free energy ΔG of -10.2 kcal/mol, with an energy difference of 5.3 kcal/mol between the two possible protonated conformers. Graphical abstract Recurrence and Noise signal performance of BPMMP as corrosion inhibitor.
Keyphrases
- density functional theory
- metal organic framework
- systematic review
- aqueous solution
- ionic liquid
- visible light
- magnetic resonance imaging
- transcription factor
- air pollution
- computed tomography
- magnetic resonance
- machine learning
- deep learning
- molecular dynamics simulations
- iron deficiency
- big data
- optical coherence tomography
- electron transfer
- case control