基于量子化学和分子模拟优选氨基酸缓蚀剂OA

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 is-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.