物理化学学报 >> 2013, Vol. 29 >> Issue (10): 22212221-2231.doi: 10.3866/PKU.WHXB201307301

电化学和新能源 上一篇    下一篇

嘧啶衍生物对钢在盐酸溶液中的缓蚀作用

李向红1,2, 谢小光1   

  1. 1 云南大学化学科学与工程学院, 昆明 650091;
    2 西南林业大学理学院, 昆明 650224
  • 收稿日期:2013-05-22 修回日期:2013-07-25 发布日期:2013-09-26
  • 通讯作者: 李向红 E-mail:xianghong-li@163.com
  • 基金资助:

    国家自然科学基金(51361027)资助项目

Inhibition Effect of Pyrimidine Derivatives on the Corrosion of Steel in Hydrochloric Acid Solution

LI Xiang-Hong1,2, XIE Xiao-Guang1   

  1. 1 School of Chemical Science and Technology, Yunnan University, Kunming 650091, P. R. China;
    2 Faculty of Science, Southwest Forestry University, Kunming 650224, P. R. China
  • Received:2013-05-22 Revised:2013-07-25 Published:2013-09-26
  • Contact: LI Xiang-Hong E-mail:xianghong-li@163.com
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (51361027).

摘要:

采用失重法、动电位极化曲线、电化学阻抗谱(EIS)、量子化学计算研究了两种嘧啶衍生物(2-羟基嘧啶(HP)和2-巯基嘧啶(MP))在1.0-5.0 mol·L-1 HCl溶液中对冷轧钢(CRS)的缓蚀作用. 结果表明: HP和MP在1.0 mol·L-1 HCl溶液中对冷轧钢具有良好的缓蚀作用, 且在钢表面的吸附符合Langmuir吸附等温式. 缓蚀率随缓蚀剂浓度的增加而增大, 但随盐酸浓度的增加而减小.求出了相应的吸附热力学参数(吸附平衡常数(K),吸附自由能(ΔG0))和腐蚀动力学参数(表观活化能(Ea)、指前因子(A)、腐蚀速率常数(k)、动力学常数(B)), 并根据这些参数讨论了缓蚀作用机理. 动电位极化曲线表明, MP和HP均为混合抑制型缓蚀剂; EIS谱呈单一容抗弧,电荷转移电阻随缓蚀剂浓度的增加而增大. 两种嘧啶化合物的缓蚀率排序为MP>HP. 量子化学计算结果表明,MP比HP更具吸附活性,缓蚀性能的理论计算和实验结果相一致.

关键词: 缓蚀剂, 2-羟基嘧啶, 2-巯基嘧啶, 钢, 盐酸, 吸附, 量子化学计算

Abstract:

The inhibition effect of two pyrimidine derivatives, 2- hydroxypyrimidine (HP) and 2- mercaptopyrimidine (MP), on the corrosion of cold rolled steel (CRS) in 1.0-5.0 mol·L-1 HCl is investigated by mass loss, potentiodynamic polarization curves, electrochemical impedance spectroscopy (EIS), and quantum chemical calculations. The results show that HP and MP are both good inhibitors of corrosion of CRS in 1.0 mol·L-1 HCl solution. The adsorption of these inhibitors onto the CRS surface obeys the Langmuir adsorption isotherm. Inhibition efficiency increases with inhibitor concentration, and decreases with hydrochloric acid concentration. The thermodynamic parameters of adsorption (adsorption equilibrium constant (K) and adsorption free energy (ΔG0)) and kinetic parameters of corrosion (apparent activation energy (Ea), pre-exponential factor (A), corrosion rate constant (k), and kinetic reaction constant (B)) are also calculated. Based on these parameters, the mechanism of inhibition is discussed. Potentiodynamic polarization curves show that HP and MP act as mixed-type inhibitors. EIS exhibit one capacitive loop, and the charge transfer resistance increases with inhibitor concentration. The results of quantum chemical calculations indicate that MP exhibits higher adsorptive ability than HP, which is in good agreement with the experimental data.

Key words: Corrosion inhibitor, 2-Hydroxypyrimidine, 2-Mercaptopyrimidine, Steel, Hydrochloric acid, Adsorption, Quantumchemical calculation

MSC2000: 

  • O646