Triazole derivatives as corrosion inhibitors for mild steel in hydrochloric acid solution

The title compounds 1-(4,5-dihydro-3-phenyl pyridine-1-yl)-2-(1H-1,2,4-triazole-1-yl) ethyl ketones were studied as a corrosion inhibitor in a mild steel in 1 mol/L hydrochloric acid solution using weight loss measurement, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS). Results indicated that these compounds had excellent inhibition properties. Polarization curves indicated that the inhibitor behaved mainly as mixed-type inhibitor. The EIS results showed that the charge transfer controlled the corrosion process in the uninhibited and inhibited solutions. Adsorption of the inhibitor on the mild steel surface followed Langmuir s adsorption isotherm with negative value of the free energy of adsorption ΔG°ads. The thermodynamic parameters of adsorption were determined and discussed.