盐酸介质中Br?nsted酸离子液体对Q235钢的缓蚀行为

Corrosion Inhibition of Q235 Steel in HCl Solution by Br?nsted Acid Ionic Liquid

利用电化学方法研究了Bronsted酸离子液体1-甲基-3-（4-磺酸基丁基）咪唑硫酸氢盐（[（CH2）4SO3HMIm][HSO4]）在0.5 mol/L HCl溶液中对Q235钢的缓蚀作用。结果表明：25℃下该酸性离子液体浓度在0-14 mmol/L时,缓蚀率随浓度增加而增加;浓度在14-16 mmol/L时,缓蚀率随浓度增加而减小;离子液体浓度在14 mmol/L时,缓蚀率可达80.7%。动电位极化曲线结果表明,该离子液体是一种混合型缓蚀剂。Q235钢表面腐蚀前后的SEM结果证实了该酸性离子液体在盐酸介质中有缓蚀能力。XPS分析表明,在Q235钢表面存在离子液体分子吸附形成的保护膜,抑制了析氢和Fe溶解反应。

The inhibition effect of Bronsted acid ionic liquids（BAIL） 1-methyl-3-（4-sulfonic acid）butyl imidazolium hydrogen sulfate（[（CH2）4SO3HMIm][HSO4]） on the corrosion of Q235 steel in0.5 mol/L HCl solution was investigated by electrochemical measurements. The results showed that the BAIL could suppress the corrosion process of Q235 steel in HCl solution at 25 ℃through adsorption. The inhibition efficiency increased with the increasing concentration of BAIL in the range 0-14 mmol/L, but decreased with the increasing concentration of BAIL in the range14-16 mmol/L. The best inhibition efficiency was 80.7% for the solution with 14 mmol/L BAIL.The potentiodynamic polarization curves revealed that the BAIL could act as a mixed-type inhibitor. SEM observation of Q235 surface showed that the adsorption of inhibitor molecules on Q235 surface could form a film of BAIL, and which could prevent both the hydrogen evolution and iron dissolution. This inhibition mechanism was proved further by the results of XPS analysis.