Experimental and Theoretical Study of Corrosion Inhibition of Mild Steel in 1.0 M HCl Medium by 2(-4( hloro phenyl-1H- benzo[d]imidazol)-1-yl)phenyl)methanone

Abstract

The 2(-4(chloro phenyl-1H-benzo[d]imidazol)-1-yl)phenyl)methanone (CBIPM) was synthesized and tested as a corrosion inhibitor for mild steel in 1.0 M HCl solution using electrochemical and spectroscopy measurements. Results obtained showed that this compound has a good inhibition properties for mild steel corrosion in acidic medium which its inhibition efficiency value reaches 98.9 % at 10-3 M. So, the potentiodynamic polarization curves showed that the CBIPM has a mixed type inhibitor. In addition, it is shown that the obtained results were confirmed by the UV-vis spectroscopic measurements. It is found that the inhibitor forms a complex with Fe 2+ ion. On the other hand, the experimental results were completed by quantum chemical calculations using DFT method at the B3LYP/6-31G* level of theory. It is found that the theoretical and experimental results are in good agreement.

Adsorption and Inhibition Mechanisms of New Pyrazole Derivatives for Carbon Steel Corrosion in Hydrochloric Acid Solutions Based on Experimental, Computational, and Theoretical Calculations

“…E LUMO , E HOMO , Δ E , global electronegativity ≪χ≫, global hardness ≪η≫, and electrons transferred ≪Δ N 110 ≫ from occupied organic molecule orbitals to vacant orbitals of metal surface. With Φ = χ­(Fe110) = 4.82 eV, the work function (eq ) explains the theoretical value of χ in Fe(110) …”

“…E LUMO , E HOMO , Δ E , global electronegativity ≪χ≫, global hardness ≪η≫, and electrons transferred ≪Δ N 110 ≫ from occupied organic molecule orbitals to vacant orbitals of metal surface. With Φ = χ(Fe110) = 4.82 eV, the work function (eq ) explains the theoretical value of χ in Fe(110) normalΔ E = E normalL normalU normalM normalO − E normalH normalO normalM normalO χ = 1 2 ( E H O M O + E L U M O ) η = 1 2 ( E H O M O − E L U M O ) normalΔ N 110 = χ F e 110 − χ normali normaln normalh 2 ( η normalF normale 110 + η i n h ) = normalΦ − χ normali normaln normalh 2 η n...…”

“…With Φ = χ(Fe110) = 4.82 eV, the work function ( eq 7 ) explains the theoretical value of χ in Fe(110). 39 …”

Electrochemical and Quantum Chemical Studies on Corrosion Inhibition Performance of 2,2'-(2-Hydroxyethylimino)bis[N-(alphaalpha-dimethylphenethyl)-N-methylacetamide] on Mild Steel Corrosion in 1M HCl Solution

“…These organic compounds reduce the metal dissolution by the absorption on the metal surfaces 12 . The adsorption and inhibition efficiency of these compounds greatly depend on the electron density around the hetero atoms, the number of adsorption active centers in the molecule and their surface charge density, molecular size, mode of adsorption and formation of metallic complexes [10][11][12][13][14][15][16][17][18][19][20][21] . However, the choice of inhibitors are based on the two considerations, first economic consideration and second the presence of the electronegative atoms such as N,O in the relatively long compounds.…”

“…However, the choice of inhibitors are based on the two considerations, first economic consideration and second the presence of the electronegative atoms such as N,O in the relatively long compounds. Thermodynamic model is an important tool used for analyzing the corrosion inhibition mechanism of inhibitors and their adsorption on the metal surface 14,15 . Using the type of adsorption isotherm that the molecule follows for the adsorption on mild steel surface, the values of thermodynamic parameters such as adsorption equilibrium constant (K ads ) and free energy change of adsorption(ΔG ads ) can be calculated and used for predicting the adsorption and inhibition mechanism.…”