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Cluster/polarized continuum models for density functional theory investigations of benzimidazole corrosion inhibitors at metal/solution interface

Lashgari, M ; Sharif University of Technology | 2006

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  1. Type of Document: Article
  2. DOI: 10.5006/1.3278266
  3. Publisher: National Assoc. of Corrosion Engineers International , 2006
  4. Abstract:
  5. The molecular behavior of some benzimidazole (C7H 6N2) derivatives as corrosion inhibitors ojiron in hydrochloric acid (HCl) solution was investigated quantum electrochemically via the inhibitors' chemical potential (μ), molecular softness (σ), and the extent of charge transfer from the inhibitor to the metal (ΔN). These quantities were obtained from density functional theory (DFT) calculations for three models, i.e., isolated inhibitors (in vacua), inhibitors in solution, and, finally, inhibitors in electrical double layer (EDL). In these models, the effects of solvent, substrate, and electric field were considered using a polarized continuum model, iron Fe13(9,4) cluster, and a finite-normal-homogeneous electric field. The investigations show that at the metal/solution interphase, the desolvation of benzimidazole takes place more easily than in the bulk of solution. Moreover, as the molecule enters EDL, an abrupt increase in μ and σ is observed. The calculations of interaction energies show that among the various possible adsorption modes of the inhibitor molecule on the iron surface, the vertical adsorption via a nitrogen lone pair is predominant. Finally, a relatively good correlation is observed between inhibitor efficiency and individual quantities of μ, σ, and ΔN. Moreover, it is observed that these correlations are improved as the model changes from a simple-ideal form (isolated inhibitor) to a more sophisticated-realistic one (inhibitors at metal/solution interphase). © 2006, NACE International
  6. Keywords:
  7. Benzimidazole corrosion inhibitors ; Cluster model ; Electric double layers ; Polarized continum model ; Solution interface ; Charge transfer ; Corrosion inhibitors ; Electrochemical corrosion ; Hydrochloric acid ; Interfaces (materials) ; Probability density function
  8. Source: Corrosion ; Volume 62, Issue 3 , 2006 , Pages 199-206 ; 00109312 (ISSN)
  9. URL: https://meridian.allenpress.com/corrosion/article-abstract/62/3/199/162615/Cluster-Polarized-Continuum-Models-for-Density?redirectedFrom=fulltext