[EMIM]HSO_4离子液体的合成及其在氧化铝电解中的应用  

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

作　　者：马江华[1] 李玉平[1] 李会泉[1] 张懿[1] 

机构地区：[1]中国科学院过程工程研究所绿色过程与工程重点实验室

出　　处：《过程工程学报》2007年第6期1083-1088,共6页The Chinese Journal of Process Engineering

基　　金：国家自然科学基金资助项目(编号:50234040);中国科学院'十五'知识创新工程重大基金资助项目(编号:KCCX1-SW-22)

摘　　要：以N-甲基咪唑为原料合成了[EMIM]HSO_4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2.890S-cm2/mol,满足电解质要求.20℃时测得Al2O3在[EMIM]HSO4中的溶解度为3.81g/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-0.26V发生铝的欠电位沉积,-0.54V发生铝的沉积,电解过程受扩散控制.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 voltammrnetry 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·cm^2/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.

关 键 词：离子液体 [EMIM]HSO4 氧化铝 溶解度 电沉积 

分 类 号：O646.5[理学—物理化学]