Triazole derivative as new and effective corrosion inhibitor for carbon steel in hydrochloric acid: Electrochemical and quantum chemical studies

The corrosion inhibition properties of triazole derivative via 3,4-diamino-1,2,4-triazole (TRD) were investigated by the electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization methods. The results of electrochemical research revealed that the TRD was adsorbed on the metal surface by adsorption mechanism and behave as mixed type inhibitor. The Among TRD exhibited maximum efficiency of 90% at 10-3M. The inhibition mechanism was analyzed by the potential of zero charge (Epzc) measurement at the solution/metal interface. The adsorption behaviour of the 3,4-diamino-1,2,4-triazole on Fe (110) surface was investigated by Monte Carlo simulations to verify their corrosion inhibition efficacies.

Corrosion inhibition of austenitic stainless steel by clay in polluted phosphoric acid with presence of SiC abrasif

Stainless steels have many properties mechanical and chemical resistances resulting from the formation of the protective layer (passive film) on their surface which prevents the metal to react with corrosive environments such as, phosphoric acid. This acid contains various impurities, including agressive agents and solid particles of gypsum, increase the risk of corrosion damage depending on the type of stainless steel used. In addition, it has been show that abrasion-corrosion causes an acceleration electrochemical process leading to a decrease in the resistance of materials. This work is to find a solution through an ecological inhibitor. That why we have been studied the effect of crude clay on corrosion behavior of Alloy 31 in polluted phosphoric acid with abrasive by electrochemical impedance spectroscopy (EIS) . The clay was characterized by X-ray fluorescence spectroscopy (FX), X-ray diffraction (DRX) and infrared spectroscopy (IR). EIS exhibited that resistance of Alloy 31 increased with increase the concentration of inhibitor

Corrosion inhibition of austenitic stainless steel by clay in polluted phosphoric acid with presence of SiC abrasif

Stainless steels have many properties mechanical and chemical resistances resulting from the formation of the protective layer (passive film) on their surface which prevents the metal to react with corrosive environments such as, phosphoric acid. This acid contains various impurities, including agressive agents and solid particles of gypsum, increase the risk of corrosion damage depending on the type of stainless steel used. In addition, it has been show that abrasion-corrosion causes an acceleration electrochemical process leading to a decrease in the resistance of materials. This work is to find a solution through an ecological inhibitor. That why we have been studied the effect of crude clay on corrosion behavior of Alloy 31 in polluted phosphoric acid with abrasive by electrochemical impedance spectroscopy (EIS) . The clay was characterized by X-ray fluorescence spectroscopy (FX), X-ray diffraction (DRX) and infrared spectroscopy (IR). EIS exhibited that resistance of Alloy 31 increased with increase the concentration of inhibitor

Synthesis, NMR characterization, DFT and anti-corrosion on carbon steel in 1M HCl of two novel 1,5-benzodiazepines

Benzodiazepines are known for their variety of applications. Herein, the corrosion inhibition efficiency on carbon steel in 1 M HCl solution in the presence and absence of two synthesized benzodiazepines 4-(2-Oxopropylidene)-1-propargyl-1,2,4,5-tetrahydro-3H-1,5-benzodiazepin-2-one (PTB) and 1-decyl-4-(2-oxopropylidene)-1,2,4,5-tetrahydro-3H-1,5-benzodiazepine-2-one (DTB) was investigated using potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) methods at various concentrations from 10−3 to 10−6 K. The obtained structures were characterized using NMR spectroscopy. Potentiodynamic polarization measurements showed that 1,5-benzodiazepine derivatives act as a mixed type inhibitor. The various parameters of activation determining the kinetic data such as energy, enthalpy and entropy of the inhibitors were evaluated and discussed. The adsorptive behavior of PTB and DTB followed Langmuir-type isotherm. The standard free energies of adsorption were negative due to better inhibition performance. DFT calculations at the B3LYP/6-31 + G (d,p) level of theory in polarizable continuum model reveal that the high inhibition of efficiency of DTB compared with PTB may refer mainly to the easy electron transfer from the former to the carbon steel surface. © 2019 Elsevier B.V

The inhibition of carbon steel corrosion in hydrochloric acid media using 2-[(5-methyl-isoxazol-3-yl)-methyl]-benzimidazole

Carbon steel corrosion inhibition in a hydrochloric acid solution by 2-[(5-methyl-isoxazol-3-yl)-methyl]-benzimidazole (MMB) has been studied by electrochemical techniques (PDP and EIS). Results showed that the inhibition efficiency increases with higher MMB concentration, and the maximum value of 86.6% was obtained at 10-3 M concentration. The prepared benzimidazole inhibitor showed higher inhibition efficiency upon raising the solution temperature from 303 to 333 K. Corrosion current density decreased from 660.9 µA cm-2 (blank) to 97.8 µA cm-2 (MMB) and charge transfer resistance increased from 20.2 Ω cm2 (blank) to 150.8 Ω cm2 (MMB). PDP studies showed that MMB is a mixed type inhibitor. The adsorption of this compound onto the carbon steel surface in a 1 M HCl solution followed the Langmuir adsorption isotherm, and the value of the standard free energy of adsorption ( ΔG° ads ) is associated to. © 2021, Sociedade Portuguesa de Electroquimica. All rights reserved

Performance evaluation and assessment of the corrosion inhibition mechanism of carbon steel in HCl medium by a new hydrazone compound: Insights from experimental, DFT and first-principles DFT simulations

In the present work, a new hydrazone compound, namely N'-[(Z)-(4-chlorophenyl)methylidene]-2-(5-methoxy-2-methyl-1H-indol-3-yl)acetohydrazide, noted HTH, was selected to protect carbon steel against corrosion in 1.0 mol/L HCl. Different chemical, electrochemical, and surface characterization techniques such as scanning electron microscope coupled with X-ray energy dispersion (SEM/EDX) were used to investigate the corrosion inhibition performance. Electrochemical data showed that the effectiveness of the inhibitor improved with increasing concentration, reaching 98% at the optimal concentration of 10-3 mol/L. The results of potentiodynamic polarization measurements showed that hydrazone acted as a mixed-type inhibitor. The EIS results showed an increase in polarization resistance accompanied by a noticeable decrease in Ceff,dl values. In the temperature range of 303 K-333 K, hydrazone protected carbon steel by 89%, showing high resistance to temperature effect. The analysis of the steel surface by SEM/EDX confirmed that the effectiveness of the hydrazone was attributed to the formation of a protective layer on the surface of the metal. Quantum chemical calculations revealed insights into the chemical reactivity of the tested hydrazone while first-principles density functional theory (DFT) and molecular dynamics (MD) simulation supported the experimental conclusions and showed outstanding adsorption ability of HTH on the Fe(110) surface. First-principles DFT simulations showed that the HTH molecule was more stable in a parallel adsorption mode