Electrochemical Study on the Inhibition of Aluminum Corrosion in Acidic Medium by Newly Synthesized Adsorbable Organic Compound

Aluminum and its alloys are widely used in many industries such as reaction vessels, pipes, machinery, and chemical batteries due to their excellent combination of properties, e.g. goodcorrosion resistance, excellent thermal conductivity, high strength to weight ratio, easy to deform,and high ductility [1]. The most important feature of aluminum is its corrosion resistance due tothe presence of a thin, adherent, and protective surface oxide film. However, when exposed to aggressive environments, such as the use of acid solutions for pickling, chemical andelectrochemical etching of aluminum, industrial acid cleaning, cleaning of oil refinery equipment, oil well acidizing and acid descaling, these processes usually lead to substantial loss of the metaldue to corrosion. The failure of aluminum equipment due to acid corrosion in industries is widelyreported, and the use of chemical inhibitors is the most practical and cost effective by means of controlling corrosion of metals in acid solutions. There is always a need for developing neworganic corrosion inhibitors result from a number of inhibitors of acid corrosion of aluminum istoxic, non-biodegradable and expensive. In the present work, new organic compound (Fig. 1) was synthesized and its inhibiting action on the corrosion of Al in sulfuric acid was investigated bymeans of potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). Electrochemical measurements were carried out by Zahner Ennium and a conventional threeelectrode system was used throughout this work. Saturated Ag/AgCl electrode, a Pt wire and an Al disk electrode were employed as the reference, counter and working electrodes, respectively.The experimental results indicate that the newly synthesized compound shows excellent inhibition efficiencies against the corrosion of Al in acidic solution. The adsorption of organiccompound onto the Al surface followed the Langmuir adsorption model with the negative free energy of adsorption. Quantum chemical calculations were employed to give further insight into the mechanism of inhibition action of organic compound

کلیدواژه ها:

Aluminum ، Corrosion ، Potentiodynamic polarization ، Electrochemical impedance spectroscopy