Shandong Science

   

Optimization of amino acid corrosion inhibitors based on quantum chemistry and molecular simulation

LI Junyi, DONG Xiaotong, ZHOU Haigang, WANG Tingyi, WU Chunlei   

  1. Sinopec Shengli Oilfield Technical Testing Center, Dongying 257000, China
  • Received:2025-06-18 Accepted:2025-08-27 Online:2026-01-27
  • Contact: LI Junyi E-mail:lijunyi0425@163.com

Abstract: In this study, a multiscale computational approach combining density functional theory calculations with all-atom molecular dynamics (MD) simulations was employed to systematically evaluate the corrosion inhibition performance of 20 amino acids at oil–gas pipeline interfaces. A three-dimensional evaluation system integrating “electronic structure–adsorption behavior–practical inhibition” was established to reveal the highly efficient inhibition mechanism of tryptophan in acidic and asphaltene-containing environments. Quantum chemical calculations show that tryptophan has the lowest molecular orbital energy gap (3.42 eV), with its frontier molecular orbitals highly localized on the aromatic rings and nitrogen-containing heterocyclic rings, endowing it with notable electronic activity. MD simulations reveal a strong negative correlation (R2 = 0.91) between adsorption energy and energy gap. Tryptophan exhibits the most favorable interfacial binding characteristics under acidic conditions (?944.88 kcal/mol) and during co-adsorption with oleic acid (?1,608.25 kcal/mol). Strong electrostatic interactions between the carboxyl oxygen atoms and the Fe(110) surface (electrostatic potential = ?32.06 kcal/mol) form the core adsorption sites. Experimental validation shows that tryptophan achieves a corrosion inhibition efficiency of 92.3% at a concentration of 140 mg/L, with a deviation of less than 5% from theoretical predictions. Overall, the cross-scale computational method developed in this study establishes an accurate linkage between electronic structure and macroscopic performance, providing a theoretical paradigm for molecular design and engineering application of green corrosion inhibitors.

Key words: amino acid, corrosion inhibitor, quantum chemistry, molecular simulation, adsorption

CLC Number: 

  • X741

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