Theoretical Study and Adsorption Behavior of Urea on Mild Steel in Automotive Gas Oil (AGO) Medium
Nleonu Emmanuel Chile,
Rajesh Haldhar,
Ubaka Kelechi Godffrey,
Onyemenonu Christopher Chijioke,
Ezeibe Anderson Umezuruike,
Okeke Pamela Ifeoma,
Mong Oke Oke,
Hamza Ichou,
Nadia Arrousse,
Seong-Cheol Kim,
Omar Dagdag,
Eno E. Ebenso,
Mustapha Taleb
Affiliations
Nleonu Emmanuel Chile
Chemistry Department, Federal Polytechnic Nekede, Owerri 460114, Nigeria
Rajesh Haldhar
School of Chemical Engineering, Yeungnam University, Gyeongsan 38541, Korea
Ubaka Kelechi Godffrey
Chemistry Department, Federal Polytechnic Nekede, Owerri 460114, Nigeria
Onyemenonu Christopher Chijioke
Chemistry Department, Federal Polytechnic Nekede, Owerri 460114, Nigeria
Ezeibe Anderson Umezuruike
Chemistry Department, Federal Polytechnic Nekede, Owerri 460114, Nigeria
Okeke Pamela Ifeoma
Department of Basic Science, Alvan Ikoku College of Education, Owerri 460114, Nigeria.
Mong Oke Oke
Department of Mechanical Engineering, Federal Polytechnic Nekede, Owerri 460114, Nigeria
Hamza Ichou
Centre d’élaboration de Matériaux et d’études Structurales, Université Toulouse III, UPS, 118 Route Narbonne, F-31062 Toulouse, France
Nadia Arrousse
Laboratory of Engineering, Organometallic, Molecular and Environment (LIMOME), Faculty of Science, University Sidi Mohamed Ben Abdellah, Fez 1796, Morocco
Seong-Cheol Kim
School of Chemical Engineering, Yeungnam University, Gyeongsan 38541, Korea
Omar Dagdag
College of Science, Engineering and Technology, University of South Africa, Johannesburg 1710, South Africa
Eno E. Ebenso
College of Science, Engineering and Technology, University of South Africa, Johannesburg 1710, South Africa
Mustapha Taleb
Laboratory of Engineering, Organometallic, Molecular and Environment (LIMOME), Faculty of Science, University Sidi Mohamed Ben Abdellah, Fez 1796, Morocco
The continuous search for eco-friendly corrosion inhibitors due to differences in corrosive media remains an important point in corrosion control. The experimental studies on the corrosion inhibition of urea on mild steel in automotive gas oil (AGO) was conducted using gasometric techniques and scanning electron microscope (SEM). The theoretical approach on the density functional theory (DFT) on the urea molecule was carried out using Gaussian 09 software. The adsorption behavior of urea molecules on the surface of the mild steel was analyzed using Frumkin and Flory-Huggins adsorption isotherms models and Gibb’s free energy, respectively. The result of the experimental study shows a poor corrosion inhibitory effect of urea on mild steel in automobile gas oil (AGO) medium as the inhibition efficiency decreased from 69.30% in week 1 to 12% in week 11 at 200 ppm of inhibitor. The adsorption of urea on the mild steel surface obeys Frumkin’s adsorption isotherm model. Gibb’s free energy of adsorption of urea molecules onto mild steel surface revealed a physisorption mechanism. SEM results showed the non-inhibitive nature of urea on the studied mild steel. Quantum chemical parameters such as HOMO, LUMO, electron affinity, electronegativity, and the fraction of electrons transferred to the metal surface were calculated and interpreted to compare the experimental and theoretical results. The theoretical findings in the current investigation were not in agreement with the experimental result, thereby creating a need for further study using the electrochemical method.
