硫酸介质中四唑类化合物对紫铜的缓蚀作用

摘要

采用动电位极化曲线和电化学阻抗谱( EIS)技术,研究5-(4 -羟苯基)-1,2,3,4-四唑(4- HPTT)和5-(4-氨苯基)-1,2,3,4-四唑(4- APTT)在暴露于空气的0.5 mol/L H2SO4介质中对紫铜的缓蚀作用.结果表明:在0.5 mol/L H2SO4溶液中,4- HPTT和4- APTT对紫铜的缓蚀效率随浓度的增加而增大,当4- HPTT和4- APTT浓度为0.25 mmol/L时,缓蚀效率分别达到99.3％和97.6％；4- HPTT为阴极型缓蚀剂,而4- APTT为混合型缓蚀剂；加入4 - HPTT和4 - APTT后紫铜的腐蚀控制步骤由活化和扩散的混合控制过程改变为电荷转移过程；4- HPTT和4 - APTT在紫铜/溶液界面的吸附遵循Langmuir吸附等温式.%Two 5-substituted tetrazoles,5-(4-hydroxyphenyl)-l,2,3,4-tetrazoles(4-HPTT) and 5-(4-amin-ophenyl)-l ,2,3,4-tetrazoles(4-APTT) ,as copper corrosion inhibitors in aerated 0. 5 mol/L H2SO4 solution were investigated by potentiodynamic polarization, electrochemical impedance spectroscopy ( EIS ). Results indicated that inhibition efficiencies of 4-HPTT and 4-APTT increased with increasing of inhibitor concentration in 0. 5 mol/L H2S04 solution,and inhibition efficiency of 4-HPTT and 4-APTT reached 99. 3% and 97.6% at 0. 25 mmol/L. 4-HPTT was cathodic-type inhibitor,but 4-APTT was mixed-type inhibitor. Corrosion control step shifted from the mixed control process by activation and diffusion to the control process of charge transfer process after adding 4-HPTT and 4-APTT into 0. 5 mol/L H2SO4 solution. The adsorption of 4-HPTT and 4-APTT on copper/solution surface obeyed the Langmuir isotherm.