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›› 2007, Vol. 7 ›› Issue (6): 1083-1088.

• 反应与分离 • 上一篇    下一篇

[EMIM]HSO4离子液体的合成及其在氧化铝电解中的应用

马江华,李玉平,李会泉,张懿   

  1. 武汉科技大学 钢铁冶金与资源利用省部共建教育部重点实验室
  • 出版日期:2007-12-20 发布日期:2007-12-20

Synthesis of 1-Ethyl-3-methylimidazolium Hydrogen Sulfate and Its Application in the Electrolysis of Aluminum

MA Jiang-hua,LI Yu-ping,LI Hui-quan,ZHANG Yi   

  1. Key Laboratory of Ferrous Metallurgy and Resources Utilization, Ministry of Education, Wuhan University of Science and Technology
  • Online:2007-12-20 Published:2007-12-20

摘要: 以N-甲基咪唑为原料合成了[EMIM]HSO4离子液体,采用红外光谱、核磁氢谱和热分析对产物进行了表征,并测定了与电解相关的物理性质,如密度、表面张力、粘度和电导率等,通过研究Al2O3在[EMIM]HSO4离子液体中的溶解度和电化学行为,探讨了其直接电解的可能性. 结果表明,[EMIM]HSO4在加热至270℃前比较稳定,密度和粘度均随温度升高而减小,在100℃时摩尔电导率为2.890 S×cm2/mol,满足电解质要求. 20℃时测得Al2O3在[EMIM]HSO4中的溶解度为3.81 g/L,满足直接电沉积对溶解度的要求. Al2O3在Pt电极上能发生电沉积,在-0.26 V发生铝的欠电位沉积,-0.54 V发生铝的沉积,电解过程受扩散控制.

关键词: 离子液体, [EMIM]HSO4, 氧化铝, 溶解度, 电沉积

Abstract: 1-Ethyl-3-methylimidazolium hydrogen sulfate ([EMIM]HSO4) was synthesized with N-methylimidazolium as raw material and characterized by using FT-IR and TG-DTG-DTA and DSC measurements. Some physical properties concerned in aluminum electrolysis, such as density, surface tension, electrical conductivity and viscosity of [EMIM]HSO4, were investigated. The solubility and electrochemical behavior of alumina in [EMIM]HSO4 was studied by using inductively coupled plasma-atomic emission spectrometer (ICP-AES) and cyclic voltammmetry measurements. The results showed that [EMIM]HSO4 was very stable at the temperatures below 270℃, its density and viscosity decreased rapidly with increase of temperature, and molar conductivity reached 2.890 S×cm2/mol at 100℃, demonstrating that [EMIM]HSO4 could be used as electrolyte. The solubility of alumina in [EMIM]HSO4 at 20℃ was 3.81 g/L, suggesting that this system might satisfy the electrolysis of alumina, alumina could be reduced to aluminum at a platinum electrode, with normal deposition at -0.54 V and under potential deposition (UPD) at -0.26 V, and the deposition was a diffusion-controlled process.

Key words: ionic liquids, 1-ethyl-3-methylimidazolium hydrogen sulfate, alumina, solubility, electrochemical deposition