Adsorption and corrosion inhibitive properties of some organic molecules on iron electrode in sulfuric acid
Adsorption and corrosion inhibitive properties of some organic molecules on iron electrode in sulfuric acid
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DOI：
10.1016/s0010-938x(01)00166-4
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发表时间：
2002-08
影响因子：
8.3
通讯作者：
Lj.M. Vračar;D. Draẑić
中科院分区：
文献类型：
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作者：
Lj.M. Vračar;D. Draẑić
研究了2-萘磺酸、2，7-萘二磺酸和2-萘酚-3，6-二磺酸三种不同有机分子在0.5moldm−_3H_2SO_4溶液中在Armco-Iron电极上的吸附和缓蚀性能。结果表明，这三种有机分子具有阴极缓蚀剂的作用。缓蚀效率随苯环上取代官能团数目的增加而变化，随浓度的增加而增加。实验测得的吸附等温线符合Frumkin方程[θ/n(1−θ)n]exp(−2aθ)=Bc，当n=2(对于2-−θ)和n=3(对于2，7-−)和n=3(对于2，7-θ和2N-3，6-DSA)时，得到了最好的拟合。参数a的计算值为2.1~2.9，吉布斯能为17~2 1kJ·−~(-1)。吸附速率常数很小，说明腐蚀过程使铁表面发生永久性变化。
Adsorption and corrosion inhibitive properties of three different organic molecules: 2-naphthalenesulfonic acid, 2,7-naphthalenedisulfonic acid and 2-naphthol-3,6-disulfonic acid are investigated on Armco-iron electrode cathodically polarized, in 0.5 moldm−3H2SO4solution. The examinations show that the three organic molecules behave as a cathodic corrosion inhibitors. The inhibitive efficiency, changes with the number of functional groups substituted on benzene ring and increases with concentration. The experimentally obtained adsorption isoterms follow the Frumkin equation [θ/n(1−θ)n]exp(−2aθ)=Bc and the best fit is obtained for n=2 (for 2-NSA) and n=3 (for 2,7-NDSA and 2N-3,6-DSA). The calculated values for the parameter a are 2.1–2.9 and Gibbs energies are 17–21 kJmol−1. The adsorption rate constants are very small, proving that iron surface permanently changes due to the corrosion processes.