Examining the outstanding corrosion inhibition performance of nicotinic hydroxamic acid in acid pickling: a comprehensive study

This study introduces nicotinic hydroxamic acid (NHA) as a highly effective corrosion inhibitor in 1 M HCl, commonly used in acid pickling and cleaning processes for mild steel. NHA’s inhibitory properties were explored via electrochemical, surface morphology, and quantum chemical methods. The molecule’s carbonyl and hydroxyl groups form stable five-membered chelate complexes with metal cations. Density functional theory (DFT) with 6–31G (d, p) basis sets analyzed NHA inhibition theoretically. Corrosion prevention on steel in 1 M HCl was assessed using electrochemical methods like potentiodynamic polarization measurements (PDP) and electrochemical impedance spectroscopy (EIS). At 200 ppm, NHA exhibited a remarkable 92.75% inhibition efficiency. Its superior anti-corrosive properties stem from multiple double bonds and numerous oxygen atoms in the carbonyl and hydroxyl groups. This research establishes NHA as a potent corrosion inhibitor and elucidates its inhibitory mechanisms through combined experimental and theoretical analyses.

Graphical Abstract