علی اکبری

Corrosion of mild steel in acidic environments represents a major challenge for energy intensive industrial systems such as oil and gas production, chemical cleaning, and power generation units. Beyond material degradation and safety risks, corrosion imposes a significant energy penalty by increasing surface roughness, fluid friction, pressure losses, and heat transfer inefficiency, ultimately leading to higher operational energy consumption. In this study, the corrosion inhibition performance of O ((3 phenylfuran 2 yl)methyl)hydroxylamine (OFMHA) for AISI 1018 mild steel in 1.0 M HCl solution was systematically evaluated using electrochemical, thermodynamic, and theoretical approaches. Potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) results revealed that OFMHA functions as a mixed type inhibitor, effectively suppressing both anodic metal dissolution and cathodic hydrogen evolution reactions. The inhibition efficiency increased with inhibitor concentration, reaching a maximum value of 96.8% at an optimal concentration of 1 × 10⁻⁴ M at 298 K. EIS analysis demonstrated a pronounced increase in charge transfer resistance accompanied by a decrease in double layer capacitance, indicating the formation of a compact and stable protective film on the steel surface. Adsorption behavior followed the Langmuir isotherm, with a highly negative standard Gibbs free energy of adsorption (ΔG°ads = −38.5 kJ mol⁻¹), suggesting spontaneous adsorption involving combined physical and chemical interactions. Density Functional Theory (DFT) calculations supported the experimental findings by identifying nitrogen, oxygen, and π electron centers as key adsorption sites. By mitigating corrosion induced surface degradation and preserving interfacial integrity, OFMHA contributes to reduced energy losses, lower maintenance demands, and improved operational efficiency, highlighting its potential for sustainable and energy efficient industrial applications in acidic environments.