Understanding and predicting adsorption capacities of corrosion inhibitors on the metal surface is of great significance for designing high-performance inhibitor molecules. Herein, a computational methodology, which utilizes molecular dynamics (MD) simulation and Density Functional Theory (DFT), was adopted to investigate the inhibition performance of four hydrazone derivatives (HDZ¹-HDZ⁴) on mild steel corrosion in acidic medium. The adsorption of the four compounds on the Fe (110) surface was studied and analyzed using global and local reactivity descriptors, molecular electrostatic potential (MEP), MD, and radial distribution function (RDF). MD results showed that the binding energy of investigated compounds with the iron surface follows the order of HDZ¹ (912 kJ/mol) > HDZ² (857 kJ/mol) > HDZ³ (801 kJ/mol) > HDZ⁴ (711 kJ/mol). Furthermore, the fractional free volume (FFV) and the interaction energy were selected for the evaluation of the diffusion behavior of hydronium and chloride ions inside inhibitor films. The results showed that both factors had a vital effect on the diffusion coefficient of corrosive particles. All results proved that inhibitor molecules having a high electron-accepting ability interact actively with the iron surface. Additionally, a direct relationship was observed between the experimentally determined inhibition efficiency and the adsorption strengths obtained from DFT and MD studies.

了解和预测缓蚀剂在金属表面的吸附能力对设计高性能缓蚀剂分子具有重要意义。在本文中，采用一种利用分子动力学（MD）模拟和密度泛函理论（DFT）的计算方法来研究四种衍生物（HDZ ¹ -HDZ ⁴）对酸性介质中低碳钢的缓蚀性能。使用全局和局部反应性描述符，分子静电势（MEP），MD和径向分布函数（RDF）研究和分析了四种化合物在Fe（110）表面上的吸附。MD结果表明，所研究化合物与铁表面的结合能遵循HDZ ¹的顺序。（912 kJ / mol）> HDZ ²（857 kJ / mol）> HDZ ³  （801 kJ / mol）> HDZ ⁴（711 kJ / mol）。此外，选择自由体积分数（FFV）和相互作用能来评估抑制剂膜中水合氢和氯离子的扩散行为。结果表明，这两个因素均对腐蚀颗粒的扩散系数具有重要影响。所有结果证明，具有高电子接受能力的抑制剂分子与铁表面有效地相互作用。另外，在实验确定的抑制效率和从DFT和MD研究获得的吸附强度之间观察到直接关系。