Inedible Avocado Extract: An Efficient Inhibitor of Carbon Steel Corrosion in Hydrochloric Acid

摘要

The corrosion inhibition of inedible avocado extract (IAE) on the corrosion of carbon steel in molarhydrochloric acid has been evaluated using weight loss method, potentiodynamic polarizationmeasurements and electrochemical impedance spectroscopy. Experimental results obtained revealedthat the inhibition efficiency have increased when the concentration of the IAE have increased butdecreased with the increase in temperature. Potentiodynamic polarization measurements clearly revealthat the investigated inhibitor is a cathodic inhibitor. The effect of temperature on the corrosion behavior of carbon steel in 1 M HCl without and with addition of 2.00 g.l of IAE was studied in thetemperature range from 298 to 328 K. Electrochemical impedance data show that the addition of theIAE in the corrosive solution decreases the double layer capacitance and simultaneously increases thecharge transfer resistance of the corrosion process, facilitating the formation of an adsorbed layer overthe carbon steel surface. The IAE inhibitor adsorbed physically on the carbon steel surface follows theLangmuir adsorption isotherm. The parameters of activation energy was evaluated and discussed.