Abstract
•Novel nitrogen based heterocyclic compound (Py-OH) has been synthesized using multicomponent approach.•Py-OH performance is 94.46% (200 mg/L) at 1500 rpm.•PDP reveals that Py-OH acts as mixed type inhibitor.•SEM, EDX and AFM analyses supports Py-OH layer formation.•XPS enriched Py-OH adsorption using electrons pairs of N and S.
The present research explores the synthesis of three heterocyclic rings of pyrazol, pyran, and pyrimidine (Py-OH) in one single compound using a multicomponent synthesis approach and its application for the protection of tubular steel (Q235 steel) in acidizing solution (15% HCl) under the dynamic condition at 1500 rpm using weight loss, electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization (PDP). Py-OH's maximum inhibition performance result is 94.46% (200 mg/L). The results of EIS and PDP reveal the corrosion process is charge transfer controlled, and Py-OH acts as a mixed type inhibitor. The maximum increase in Rct value is 393.7 Ω cm2, and the decrease in icorr value is 23 μA/cm2. The adsorption of Py-OH obeyed the Freundlich isotherm. The value of Ea is 80.17 kJ/mol. The protection ability of Py-OH falls as the temperature rises from 308 K to 338 K. The results of SEM, EDX and AFM confirmed the inhibitor layer formation that corresponds to the decrease in surface roughness of Q235 steel, supporting its corrosion protection excellency. Furthermore, the results of XPS further enriched the Py-OH adsorption using the lone pair electrons residing over the N and S.