Author/Authors :
El Assyry, Abdeslam Laboratory of Polymer Physics and Critical Phenomena - Department of Physics - Faculty of Sciences Ben M'Sik - Hassan II University - Casablanca, Morocco , Touil, M'Hamed ESCTM (PCMVC Laboratory) - Faculty of Sciences - Ibn Tofail University - P.O. Box 133 - Kenitra 14000 - Morocco , Benhiba, Fouad Laboratory of Separation Processes - Faculty of Sciences - IbnTofail University - P.O. Box 133 - 14000 - Kenitra - Morocco 4Laboratory of Materials - Nanotechnology and Environment - Faculty of Sciences - Mohammed V University - Av. Ibn Battouta - P.O. Box 1014 - Agdal-Rabat - Morocco , Benali, Bouziane Laboratory of Optoelectronic - Physical Chemistry of Materials and Environment - Department of Physics - Faculty of Sciences - Ibn Tofail University - PB. 133 - 1400 - Kenitra, Morocco , Rabaâ, Hassan ESCTM (PCMVC Laboratory) - Faculty of Sciences - Ibn Tofail University - P.O. Box 133 - Kenitra 14000 - Morocco , Lakhrissi, Brahim Laboratory of Agro-Resources, Polymers and Process Engineering - Faculty of Sciences - Ibn Tofail University - PO Box 133 - 14000 - Kenitra, Morocco , Warad, Ismail Department of Chemistry and Earth Sciences - PO Box 2713 - Qatar University - Doha, Qatar , Bentiss, Fouad Laboratoire de Catalyse et de Corrosion des Matériaux (LCCM) - Faculté des Sciences - Université Chouaib Doukkali - B.P. 20 - M-24000 El Jadida - Morocco , Zarrouk, Abdelkader Laboratory of Materials - Nanotechnology and Environment - Faculty of Sciences - Mohammed V University - Av. Ibn Battouta - P.O. Box 1014 - Agdal-Rabat - Morocco
Abstract :
The adsorption behavior of Benzimidazol-2-one (Bz), 5-Methylbenzimidazol-2- one (CH3Bz) and 5-Chlorobenzimidazol-2-one (ClBz) as inhibitors for mild steel corrosion in
HCl 1M have been studied computationally using density functional theory (DFT)
calculations with the hybrid B3LYP functional. The calculations were focused on the
protonated forms of the molecules under study, seeing that these classes of inhibitors can
easily be protonated in acidic medium. The most preferred protonation centers were
determined proton affinity (PA). Fukui indices have been computed to evaluate the
nucleophilic and electrophilic sites of atoms in the molecule. The interaction of the inhibitors
with the iron surface was studied by calculating the combined energy (Ecom) and the free
energy of adsorption ( ads G ). Observable correlation was found between experimental
corrosion inhibition efficiency and the theoretical data. The molecular dynamics (MD) and
Monte Carlo (MC) simulations used show that all investigated Benzimidazol inhibitors are
positioned parallel to the metal surface reflecting the coverage of a large portion of the steel
surface.
Keywords :
Ordinary steel , Benzimidazolone , Adsorption , Density functional theory , Monte Carlo , Molecular dynamics
