Experimental and theoretical study on the corrosion inhibition of mild steel by ethyl 1-(((4-acetylphenyl)((3-(ethoxycarbonyl)-1H-p yrazol-1-yl)methyl)amino) methyl)-5-methyl-1H-pyrazole-3-carboxylate in sulfu ric acid solution

摘要

The corrosion inhibition of mild steel in 0.5 M H 2 SO 4 using ethyl 1-(((4-acetylphenyl)((3-(ethoxycarbony l)-1H- pyrazol-1-yl)methyl)amino)methyl)-5-methyl-1H-pyraz ole-3-carboxylate (APC) at 298 K have been investig ated. The study was performed using weight loss method, p otentiodynamic polarization, and electrochemical im pedance spectroscopy (EIS). The experimental results sugges t that the inhibition efficiency of this compound i ncreases with the increase in inhibitor concentration. Adsorption of this compound on mild steel surface obeys Langm uir’s isotherm. Polarization measurements proved that thi s inhibitor behave as mixed type. EIS data showed t hat the charge transfer resistance of mild steel increases in acid solution containing inhibitor. Correlation between quantum chemical calculations and inhibition effici ency of the investigated compound is discussed usin g the Density Functional Theory method (DFT).