Evaluation of the corrosion inhibition efficiency of 7-(Acetohydrazide-2-yloxy)-4-methylcoumarin in 1.0 M HCl: Experimental and theoretical approach

This study investigates the corrosion inhibition potential of 7-(acetohydrazide-2-yloxy)-4-methylcoumarin (AMC) in 1.0 M HCl, emphasizing its efficiency at varying concentrations. The inhibitory performance was evaluated using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) to assess the effectiveness of AMC's in mitigating mild steel corrosion. The results revealed that AMC exhibited a peak inhibition efficiency of 90.7 % at 0.5 mM, demonstrating its exceptional protective ability. The adsorption process was found to follow the Langmuir model, confirming the formation of a stable monolayer on metal surface. To gain deeper insights into the inhibition mechanism, Density Functional Theory (DFT) calculations were performed, revealing key electronic structure parameters and adsorption behavior of AMC at the molecular level. The findings highlight AMC a highly efficient and environmentally viable corrosion inhibitor in HCl solution, offering strong adsorption capabilities and long-term stability.