Novel Corrosion Inhibitor for Carbon Steel in Acidic Solutions Based on α-Aminophosphonate (Chemical, Electrochemical, and Quantum Studies)

• Published in: Molecules (Basel, Switzerland) Vol. 28; no. 13; p. 4962
• Main Authors: Deyab, M A, Abdeen, Marwa M, Hussien, Mohamed, E El-Sayed, Ibrahim, Galhoum, Ahmed, El-Shamy, Omnia A A, Abd Elfattah, Marwa
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 24-06-2023; MDPI
• Subjects: acid solutions; Acids; Adsorption; Carbon - chemistry; Carbon steel; Chemical inhibitors; Corrosion; Corrosion inhibitors; Corrosion potential; Corrosion rate; Electrochemistry; Electrolytes; Morphology; Nitrogen; organo-inhibitors; Spectroscopy, Fourier Transform Infrared; Steel; Steel - chemistry; Steel pipes; Sulfuric acid; Egypt; steel; adsorption; corrosion; organo-inhibitors; acid solutions
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules28134962

α-aminophosphonate (α-AP) is used as a novel corrosion inhibitor for carbon steel. The aggressive media applied in this study are HCl and H
SO
acid solutions. The findings indicate that the morphology of the α-AP compound is cubic, with particles ranging in size from 17 to 23 μm. FT-IR,
HNMR,
PNMR, and
CNMR analysis confirmed the synthesis of the α-AP molecule. It has been discovered that the compound α-AP plays an important role in inhibiting the corrosion of carbon steel in both HCl and H
SO
acids. This was identifiably inferred from the fact that the addition of α-AP compound decreased the corrosion rate. It is important to report that the maximum inhibition efficiency (92.4% for HCl and 95.7% for H
SO
) was obtained at 180 ppm. The primary factor affecting the rate at which steel specimens corrode in acidic electrolytes is the tendency of α-AP compounds to adsorb on the surface of steel through their heteroatoms (O, N, and P). This was verified by SEM/EDX results. The adsorption actually occurs through physical and chemical mechanisms via different active centers which are matched with the calculated quantum parameters. In addition, the adsorption of α-AP follows the Langmuir isotherm.