Thermodynamic and adsorption behavior of N2O4 schiff base as a corrosion inhibitor for API-5L-X65 steel in HCl solution

Abstract

The inhibition ability of N,N '-bis(2,4-dihydroxyacetophenone)-1,3-propandiimine (DHAPP) as a schiff base against the corrosion of API-5L-X65 in 1 M HCl solution was evaluated by polarization, electrochemical impedance spectroscopy, and scanning electron microscopy. Polarization studies indicated that DHAPP retards both the cathodic and anodic reactions through chemical adsorption and blocking the active corrosion sites. The adsorption of this compound obeyed the Langmuir adsorption isotherm. The inhibition effi ciency increased with inhibitor concentration and decreased with increasing temperature. EIS data analysed to equivalent circuit model showed that as the inhibitor concentration increased the charge transfer resistance of steel increased whilst double layer capacitance decreased. Kinetic and thermodynamic parameters such as activation energy, enthalpy, entropy, and Gibbs free energy of activation and adsorption were calculated. Gibbs free energy indicated that adsorption occurred through physical and spontaneous process. Scanning electron microscopy was used to study the steel surface with and without inhibitor.The inhibition ability of N,N '-bis(2,4-dihydroxyacetophenone)-1,3-propandiimine (DHAPP) as a schiff base against the corrosion of API-5L-X65 in 1 M HCl solution was evaluated by polarization, electrochemical impedance spectroscopy, and scanning electron microscopy. Polarization studies indicated that DHAPP retards both the cathodic and anodic reactions through chemical adsorption and blocking the active corrosion sites. The adsorption of this compound obeyed the Langmuir adsorption isotherm. The inhibition effi ciency increased with inhibitor concentration and decreased with increasing temperature. EIS data analysed to equivalent circuit model showed that as the inhibitor concentration increased the charge transfer resistance of steel increased whilst double layer capacitance decreased. Kinetic and thermodynamic parameters such as activation energy, enthalpy, entropy, and Gibbs free energy of activation and adsorption were calculated. Gibbs free energy indicated that adsorption occurred through physical and spontaneous process. Scanning electron microscopy was used to study the steel surface with and without inhibitor.

Investigation on Trend Removal in Time Domain Analysis of Electrochemical Noise Data Using Polynomial Fitting and Moving Average Removal Methods

“…2 Bode plots revealed one time constant for EIS response of all samples, indicating that the corrosion process is under charge transfer control in the absence and presence of different concentrations of BDAP [31]. The Bode diagrams have a similar shape throughout all tested concentrations, indicating that almost no change in the corrosion mechanism occurs due to the inhibitor addition [32][33][34]. The Bode resistance increases in the presence of inhibitor.…”

The effect of temperature on the corrosion inhibition performance of two pyrazole derivatives for mild steel in 1 M HCl: Electrochemical and FTIR investigations

“…For the present study, the activation enthalpy values (∆Ha) for both inhibitors DPC-1 and DPC-2 are positive referring to the endothermic process. As for the activation entropy (∆Sa), the values for both uninhibited and inhibited 1 M HCl solution are of positive signs, which reveal a quasi-substitution process between the pyrazole molecules (DPCsol) in solution and water molecules (H2Oads) on the steel surface [41,42].…”

Gas Corrosion of Pyrolysis Furnace Coils

“…A gravimetric method the principle of which is to determine the loss of metal samples mass during their presence in the test medium to determine the corrosion rate was applied. The corrosion rate is characterized by a mass index K m (g / m 2 •h) in a gravimetric method [10][11][12][13][14][15].…”