Electrochemical, surface and quantum chemical studies of novel imidazole derivatives as corrosion inhibitors for J55 steel in sweet corrosive environment

• Published in: Journal of alloys and compounds Vol. 712; pp. 121 - 133
• Main Authors: Singh, Ambrish, Ansari, K.R., Kumar, Ashok, Liu, Wanying, Songsong, Chen, Lin, Yuanhua
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 25-07-2017; Elsevier BV
• Subjects: Adsorption; AFM; Atomic force microscopes; Atomic force microscopy; Carbon dioxide; Contact angle; Corrosion; Corrosion inhibitors; Derivatives; EIS; Electrochemical impedance spectroscopy; High strength low alloy steels; Imidazole; J55 steel; Mathematical analysis; Medium carbon steels; Quantum chemistry; Saline water; Scanning electron microscopy; SECM; Steel; Weight loss; X ray photoelectron spectroscopy; XPS; AFM; XPS; SECM; J55 steel; Imidazole; EIS
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2017.04.072

The corrosion inhibition performance of three novel imidazole derivatives namely 2-(4-methoxyphenyl)-4,5-diphenyl-imidazole (M-1), 4,5-diphenyl-2-(p-tolyl)-imidazole (M-2) and 2-(4-nitrophenyl)-4,5-diphenyl-imidazole (M-3) for J55 steel in CO2 saturated brine solution was studied by weight loss method, electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, scanning electrochemical microscopy (SECM), contact angle, scanning electron microscope (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and quantum chemical calculation. M-1 exhibited the best inhibition efficiency of 93% at 400 mg/L concentration. The adsorption of the imidazole derivatives obeyed the Langmuir adsorption isotherm. Contact angle measurement reveals the hydrophobic nature of J55 steel in presence of inhibitors. Quantum chemical calculation well supports the experimental results.
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•J55 steel protection in 3.5% NaCl with CO2 in presence of imidazole derivatives.•Tafel curves reveal that the inhibitors are mixed type but anodically dominant.•The inhibitors obey the Langmuir isotherm and Kads and ΔG°ads are also discussed.•Examination of surface morphology by SECM and SEM.•Correlation between experimental and Quantum chemical results.