The inhibitive action of some benzimidazole derivatives namely 2-aminobenzimidazole (AB), 2-(2-pyridyl)benzimidazole (PB), 2-aminomethylbenzimidazole (MB), 2-hydroxybenzimidazole (HB) and benzimidazole (B), against the corrosion of iron (99.9999%) in solutions of hydrochloric acid has been studied using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). At inhibitor concentration range (10⁻³–10⁻² M) in 1 M acid, the results showed that these compounds suppressed both cathodic and anodic processes of iron corrosion in 1 M HCl by adsorption on the iron surface according to Langmuir adsorption isotherm. The efficiency of these inhibitors increases in the order AB>PB>MB>HB>B. Both potentiodynamic and EIS measurements reveal that these compounds inhibit the iron corrosion in 1 M HCl and that the efficiency increases with increasing of the inhibitor concentration. Data obtained from EIS were analyzed to model the corrosion inhibition process through equivalent circuit. A correlation between the highest occupied molecular orbital E_HOMO and inhibition efficiencies was sought.

中文翻译：

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苯并咪唑衍生物对1 M HCl溶液中铁腐蚀的抑制作用

某些苯并咪唑衍生物（2-氨基苯并咪唑（AB），2-（2-吡啶基）苯并咪唑（PB），2-氨基甲基苯并咪唑（MB），2-羟基苯并咪唑（HB）和苯并咪唑（B）的缓蚀作用使用电位动力学极化和电化学阻抗谱（EIS）研究了盐酸溶液中的铁（99.9999％）。在抑制剂浓度范围（10 ^-3 –10 ^-2M）在1 M酸中，结果表明这些化合物通过根据Langmuir吸附等温线吸附在铁表面上，从而抑制了在1 M HCl中铁腐蚀的阴极和阳极过程。这些抑制剂的效率以AB> PB> MB> HB> B的顺序增加。电位动力学和EIS测量均表明，这些化合物可抑制1 M HCl中的铁腐蚀，且效率随抑制剂浓度的增加而增加。分析从EIS获得的数据，以通过等效电路对腐蚀抑制过程进行建模。寻找最高占据分子轨道E _HOMO与抑制效率之间的相关性。