en گروه سطح پوشش و خوردگی Surface Coatings and Corrosion Research Paper Research Paper <p style="text-align: justify;">In this study, an&nbsp; organic compound&nbsp; inhibitor, namely N-benzyl-<em>N</em>-(4-chlorophenyl)-1<em>H</em>-tetrazole-5-amine (NBTA), was synthesized and the role of this inhibitor for corrosion protection of stainless steel (SS) exposed to 0.5 M H₂SO₄ was investigated using electrochemical, and quantum analysis. By taking advantage of potentiodynamic polarization, the inhibitory action of NBTA was found to be mainly mixed type with dominant anodic inhibition. The effectiveness of the inhibitor was also indicated using electrochemical impedance spectroscopy (EIS). Moreover, to provide further insight into the mechanism of inhibition, quantum chemical calculations of the inhibitor were performed. The adsorption of NBTA onto the SS surface followed the Langmuir adsorption model with the free energy of adsorption &Delta;G⁰_ads of of -7.88 kJ mol^-1. Quantum chemical calculations were employed to give further insight into the mechanism of inhibition action of NBTA.</p> organic inhibitor, adsorption, stainless steel, impedance, Density functional theory 19 28 http://ijmse.iust.ac.ir/browse.php?a_code=A-10-1004-1&slc_lang=en&sid=1 A. Ehsani ehsani46847@yahoo.com 180031947532846005821 180031947532846005821 Yes department of chemistry, Qom University, Qom, iran S Bodaghi bodaghi58@qom.ac.ir 180031947532846005822 180031947532846005822 No department of chemistry, Qom University, Qom, iran H Mohammad Shiri hshiri8974@qom.ac.ir 180031947532846005823 180031947532846005823 No department of chemistry, Qom University, Qom, iran H Mostaanzadeh Mostaan635@qom.ac.ir 180031947532846005824 180031947532846005824 No department of chemistry, Qom University, Qom, iran M Hadi Mhadianalyte125@qom.ac.ir 180031947532846005825 180031947532846005825 No department of chemistry, Qom University, Qom, iran