Phenethylamine's Effect on Preventing the Corrosion of Low-Carbon Steel in Acidic Environments: Theoretical and Experimental DFT Computational Investigation

Abstract

The current study employed polarization and gravimetric methods to investigate the corrosion resistance of low carbon steel in a solution with hydrochloric acid and different concentrations of phenethylamine. The inhibitor showed a high level of inhibitory effectiveness IE (%). Inhibitor's efficacy tends to decline with increasing temperature and concentration. The structure of inhibitor contains amine and ethyl groups, which are necessary for the adsorption process. These groups form a thin layer on the metal's surface and provide sufficient corrosion prevention. The thermodynamic parameters enthalpy, adsorption free energy, and entropy change were determined. Results were in line with previous research and were suitable. Adsorption and dissolution thermodynamic functions were also calculated. Moreover, DFT was used to compute thermodynamic functions of adsorption and dissolution for inhibitor. Also, energy levels of the least occupied molecular orbital (LUMO) and the energy of the most occupied molecular orbital (HOMO) were studied.