离子液体AlCl3Et 3NHCl中电沉积法制备金属铝

[Article]

物理化学学报(Wuli Huaxue Xuebao )

Acta Phys.鄄Chim.Sin .,2008,24(6)：939-944

June Received:January 21,2008;Revised:February 27,2008;Published on Web:April 9,2008.

English edition available online at ∗

Corresponding author.Email:tqi@;Tel ：+8610⁃62631710.国家重点基础研究发展计划(973)(2007CB613501)资助

ⒸEditorial office of Acta Physico ⁃Chimica Sinica

离子液体AlCl 3/Et 3NHCl 中电沉积法制备金属铝

高丽霞

王丽娜

齐

涛∗

李玉平

初景龙

曲景奎

(中国科学院过程工程研究所,绿色过程与工程院重点实验室,北京100190)

摘要：在AlCl 3/Et 3NHCl 型离子液体中铝电极上通过恒电位电解沉积制备出金属铝.测定了不同摩尔比的AlCl 3/Et 3NHCl 离子液体在不同温度下的电导率,考察了离子液体AlCl 3/Et 3NHCl 摩尔比为2/1中Al 电极上铝沉积的晶核成核过程,以及恒电位电解沉积铝的工艺条件对电流效率和沉积铝表面形貌的影响.结果表明,不同比例AlCl 3/Et 3NHCl 离子液体的电导率随温度升高而升高,符合Arrhenius 规律;在Al 电极上铝沉积的成核机理为三维瞬时成核过程;恒电位电解沉积结果表明,室温下在电位-2.4V(vs Pt)和电解时间20min 条件下,沉积铝的表面形貌比较平整致密,电流效率达73%,沉积铝的纯度达96%(w ).关键词：铝;电沉积;电化学;离子液体

中图分类号：O646

Electrodeposition of Aluminium from AlCl 3/Et 3NHCl Ionic Liquids

GAO Li ⁃Xia

WANG Li ⁃Na QI Tao ∗LI Yu ⁃Ping CHU Jing ⁃Long QU Jing ⁃Kui

(Key Laboratory of Green Process and Engineering,Institute of Process Engineering,Chinese Academy of Sciences,

Beijing 100190,P.R.China )

Abstract ：Aluminum was successfully electrodeposited on Al electrodes from aluminum chloride (AlCl 3)/triethylamine hydrochloride (Et 3NHCl)ionic liquids by the constant potential electrolysis.Electrical conductivities of AlCl 3/Et 3NHCl ionic liquids were measured as a function of the temperature and composition.The nucleation processes and the influence of experimental conditions on the current efficiency and surface morphology of aluminum electrodeposits were studied on Al electrodes from 2:1molar ratio AlCl 3/Et 3NHCl ionic liquid.The electrical conductivities of ionic liquids increased as the electrolyte temperature increased,following the Arrhenius behavior.Analyses of the chronoamperograms indicated that the deposition process of aluminium on Al substrates was controlled by instantaneous nucleation with diffusion ⁃controlled growth.Constant potential deposition experiments showed that the electrodeposits obtained on Al electrodes were dense,continuous,and well adherent,and the current efficiency was 73%at -2.4V (vs Pt)for 20min electrolysis at room temperature.The purity of aluminum electrodeposits on Al electrodes was above 96%(w ).

Key Words ：Aluminium;Electrodeposition;

Electrochemistry;

Ionic liquid

铝产量仅次于钢铁，产值占有色金属的一半，但生产耗电量巨大.2006年我国电解铝产量935万吨,产量居世界首位,综合交流电耗1.47亿千瓦时,总耗电量1372亿千瓦,占全国电力消耗总量的4.9%，而总产值不到全国GDP 的1%,因此,电解铝已成为

首屈一指的高耗能行业.传统电解铝工艺(Hall ⁃H éroult)[1]为冰晶石⁃氧化铝熔盐电解法,操作温度高达950-1000℃,能耗达13-15kWh/kg ⁃Al,且环境污染严重.因此,研发高效⁃清洁⁃节能的铝电解新技术对铝工业的协调可持续发展具有重要战略意义.

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