纯铝在两种不同类型缓蚀剂的碱性溶液中的电化学行为研究

Study on electrochemical behaviors for aluminum in alkaline solution with two different inhibitors

采用集气实验、极化曲线方法研究纯铝在4 mol/L KOH溶液中的电化学行为,溶液中分别添加碱土金属离子与EDTA、ZnO与DE后,实验结果表明铝在含0.02 mol/L EDTA和饱和Ca(OH)2、Sr(OH)2溶液与0.2 mol/L ZnO与0.3 mL/L DE溶液均具有最小的腐蚀速率。EDAX分析表明碱土金属离子与EDTA没有参与到铝表面氧化膜的组成中,说明该缓蚀剂是通过吸附在铝表面起作用的,它们是界面型缓蚀剂;而在含ZnO与DE溶液中,由于氧化锌被还原成锌,沉积在铝表面上,从而减少了析氢反应速率,属于成相型缓蚀剂。

Electrochemical behaviors of aluminum in 4 mol/L KOH solution with inhibitors were investigated by hydrogen collection and polarization curve measurement.It was found that aluminum exhibited minimum corrosion rate in a 4 mol/L KOH solution containing 0.02 mol/L EDTA,saturated Ca（OH）2 and saturated Sr（OH）2.It was also seen that the 4 mol/L KOH solution containing 0.2 mol/L ZnO and 0.3 ml/L DE provided the highest inhibition efficiency.EDAX analysis showed that alkaline metal ions and EDTA had no contribution to the formation of the surface film on aluminum,therefore the inhibition effect might be caused by the adsorption of the inhibitor on aluminum surface,which indicated that these two ions acted as interface inhibitors.However,ZnO produced its effect by depositing zinc on the aluminum surface during reduction of ZnO,which decreased the rate of hydrogen evolution.It acted as an inter-phase inhibitor.