Corrosion Inhibition Effect of 2-Chloro-1-(4-fluorobenzyl) benzimidazole on Copper in 0.5 M H2SO4 solution

2-Chloro-1-(4-fluorobenzyl)benzimidazole (CFB) is the primary intermediate in synthesizing the antiallergic drug mizolastine. In this work, we selected CFB as a candidate to replace toxic and difficult to synthesize inhibitors. Combining electrochemical experiments and Density Functional Theory (DFT) calculations, the anti-corrosion ability of CFB for copper in 0.5 M H2SO4 was explored in detail. The electrochemical test indicated that CFB was an excellent inhibitor, which could slow down copper anodic and cathodic dissolution rates. The highest eta value reached 95.2% when CFB was 10 mM. Langmuir adsorption isotherm demonstrated that CFB molecules adsorbed to the copper surface by physicochemical action. DFT calculations revealed that the benzene and imidazole rings in CFB were the active sites for adsorption. We believe this work can accumulate experience for developing drug corrosion inhibitors and promote their practical application in the industry.