摘要
研究了温度范围在723-908K的LiCl-KCl熔盐体系中MgCl2的电化学行为和热力学性质.循环伏安和方波伏安法研究表明镁离子的电化学还原过程为包含了两个电子转移的一步反应.利用Berzins和Delahay方程计算了不同温度下的镁离子的扩散系数,并通过Arrhenius公式计算了镁离子在LiCl-KCl熔盐体系中的扩散活化能.采用开路计时电位法得到了不同温度下的Mg(II)/Mg(0)体系的平衡电位,并结合电动势法计算了在LiCl-KCl熔盐体系中Mg(II)/Mg(0)体系的标准形式电位.根据不同温度下的标准形式电位,计算得到了MgCl2在LiCl-KCl熔盐体系中的熵变和焓变以及不同温度下的活度系数.
The electrochemical behavior and thermodynamic properties of MgCI2 dissolved in LiCI-KCI eutectic melts in the temperature range of 723-908 K were investigated. Cyclic and square wave voltammetry experiments indicated that the reduction of Mg ions into Mg metal occurred in a single step and involved exchange of two electrons. The diffusion coefficient （D） of Mg（II） was determined by the Berzins-Delahay equation and the Arrhenius law was validated by plotting IgD versus T^-1 for the reduction of Mg（II）. Open circuit chronopotentiometry was used to determine the equilibrium potential of Mg（ll）/Mg（0）. The standard apparent potentials of the Mg（II）/Mg（0） system and the activity coefficients of Mg（II） in LiCI-KCI eutectic melts based on a pure supercool reference state were calculated at several temperatures.
出处
《物理化学学报》
SCIE
CAS
CSCD
北大核心
2013年第8期1698-1704,共7页
Acta Physico-Chimica Sinica
基金
supported by the High Technology Research and Development Program of China(2011AA03A409)
National Natural Science Foundation of China(21103033,21101040,91226201)
China Postdoctoral Science Foundation(2013T60344)
Fundamental Research Funds for the Central Universities,China(HEUCF201310012)
Foundation for University Key Teacher of Heilongjiang Province of China(1253G016)~~
关键词
氯化物熔盐
热力学性质
MGCL2
活度系数
标准形式电位
Molten chloride
Thermodynamic property
Activity coefficient of MgCI2
Standardapparent potential
