Quinoxaline derivatives as corrosion inhibitors of carbon steel in hydrochloridric acid media: Electrochemical,DFT and monte carlo simulations studies

(e)-3-(4-methoxystyryl)-7-methylquinoxalin-2(1h)-one (smq) and 2-(4-methoxyphenyl)-7-methyl-thieno[3,2-b] quinoxaline (tmq) are new compounds of the quinoxaline derivative family,were synthesized andtested on the corrosion of carbon steel in chlorhydric acid molar media at 303 k,using various electrochemical methods (polarization curves (pdp) and electrochemical impedance spectroscopy (eis)). for each concentration,the protective power of both the compounds tested isrise with increasingof inhibitor concentration. tmq is more efficient than smq inthe medium studied; these results clearly show that the tmq is the best inhibitor. the polarization curves studies show that both compounds tested are mixed-type inhibitor in 1 m hcl media. the inhibitors react by adsorption according to langmuir isotherm. the nyquist curves presented a single capacitive loop,their diameter increases progressively with both inhibitors concentration. the double layer formed due to the increase in the charge transfer résistance. dft and monte carlo simulation studies are in good correlation with the experimental results.