Abstract: The reactivity and inhibition performance on Al (111)surface of three pyridine molecules (pyridine,3-methylpyridine and 4-methylpyridine)was studied by using the density functional theory (DFT).The results showed that the frontier orbitals of the three corrosion inhibitor molecules,including the highest occupied molecular orbital (HOMO)and lowest unoccupied molecular orbital (LUMO),were all distributed on the pyridine ring,and both the nucleophilic and electrophilic activity centers of the three molecules were mainly concentrated at the heteroatoms N atom.Moreover,all of the three corrosion inhibitor molecules could perpendicularly chemisorb on Al surface via N atom,and the order of adsorption energy agreed with the inhibition efficiency obtained by experiment.The strong effect of N-Al bonding resulted from the atomic orbits hybridization.Additionally,3-methylpyridine and 4-methylpyridine could also nearly parallel physisorb on the Al (111)surface.

Key words: corrosion inhibitor, density functional theory, pyridine derivatives, Al(111)surface, adsorption, reaction activity

摘要： 利用密度泛函理论方法研究了3种吡啶类缓蚀剂分子(吡啶、3-甲基吡啶和4-甲基吡啶)的反应活性及溶剂条件下在Al(111)表面的吸附行为。分子反应活性的量化计算结果表明,3种缓蚀剂分子的前线轨道均分布在吡啶环上,亲核和亲电活性中心均位于吡啶环的N原子上。分子与Al表面吸附的量化计算结果表明,3种分子均能与Al(111)面发生化学吸附,吸附强度顺序与实验测得的缓蚀效率顺序相一致,且缓蚀剂分子与Al(111)面的相互作用是由成键原子的轨道杂化所致。此外,3-甲基吡啶和4-甲基吡啶两个分子还能平行于Al(111)面发生物理吸附。

关键词: 缓蚀剂, 密度泛函理论, 吡啶类化合物, Al(111)表面, 吸附, 反应活性