Novel nitrogen based heterocyclic compound as Q235 steel corrosion inhibitor in 15% HCl under dynamic condition: A detailed experimental and surface analysis

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 R-ct value is 393.7 X cm(2), and the decrease in i(corr) value is 23 lA/cm(2). The adsorption of Py-OH obeyed the Freundlich isotherm. The value of E-a 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 con-firmed 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. (C) 2022 Elsevier B.V. All rights reserved.

Automated summary

This 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. The results demonstrate that Py-OH exhibits a high inhibition performance of 94.46% and acts as a mixed type inhibitor, controlling the corrosion process under dynamic conditions.