Comprehensive Investigation of 3-Phenyl-5-Isoxazolone as a Corrosion Inhibitor for Steel in Sulfuric Acid: Experimental and Theoretical Insights
摘要
The present study investigates the corrosion inhibition performance of 3-Phenyl-5-isoxazolone (PI) for steel in 0.5 M H2SO4 solution. To assess its efficiency, the influence of various PI concentrations was examined at 298 K, followed by an evaluation of temperature effects in the range of 298-338 K for an inhibitor concentration of 10−3 M. The corrosion behavior of steel was investigated using gravimetric measurements, potentiodynamic polarization (PDP), and electrochemical impedance spectroscopy (EIS). The obtained results showed that increasing PI concentration improves the inhibition efficiency, reaching 89.07% at 10−3 M. EIS measurements revealed a notable increase in charge transfer resistance (Rct) to 240.3 Ω cm2, suggesting the formation of a protective film on the steel surface as further confirmed by SEM-EDS analysis. Temperature effect studies indicated that higher temperatures accelerate the corrosion process, leading to a decrease in inhibition efficiency. The increase in activation energy from 43.81 to 78.85 kJ/mol suggests that the adsorption of PI on the steel surface occurs through a chemisorption mechanism. Theoretical calculations further supported these findings, showing strong adsorption of PI molecules through nitrogen and oxygen atoms. The experimental and computational results demonstrate that PI is an efficient, chemically adsorbed corrosion inhibitor that provides strong protection of steel in acidic environments.