氟化物熔盐中铀离子的电化学行为研究  

The Electrochemical Behavior of Uranium Ions in LiF-NaF Molten Salts

作　　者：刘刈[1] 王长水[1] 曹龙浩 郭君康 欧阳应根[1] 

机构地区：[1]中国原子能科学研究院放射化学研究所,北京102413

出　　处：《化学通报》2013年第11期1049-1052,共4页Chemistry

基　　金：国家重点基础研究发展计划(973计划)项目(2007CB209906)资助

摘　　要：采用循环伏安法和计时电位法研究了1073K下U4+在LiF-NaF熔盐中的电化学还原机理。结果表明,U4+在氟化物熔盐中的还原分为2步,分析了各步的反应电子数,确定U4+还原过程为U4++e=U3+,U3++3e=U;循环伏安曲线中2个还原峰的峰电位并不随扫速增大而显著负移,峰电流与扫速的平方根呈良好的线性关系,说明这2个还原过程均为扩散控制且是可逆反应;计算得到了1073K下U4+在LiF-NaF中的扩散系数为DU(IV)=2.58×10-5cm2/s。The electrochemical reduction mechanism in molten LiF-NaF euteetic containing UF4 at 1073K were investigated by cyclic voltammetry and ehronopotentiometry. The results indicated that the reduction process of U4＋ consists of two steps. The number of electrons exchanged at each step had been calculated and the reduction mechanism had been determined which corresponds to two reactions： U4＋ ＋ e = U3＋ , U3＋ ＋ 3e = U. The potentials of two reduction peaks do not shift negatively with increasing of scanning rate and the corresponding dependence of peak current on scanning rate has higher linearity, which confirm that the two steps are reversible and limited by diffusion. The diffusion coefficient of U4＋ in LiF-KF eutectic calculated is DU（IV） = 2.58 × 10-Scm2/s （800℃）.

关 键 词：LiF-NaF 铀离子 循环伏安 计时电位 扩散系数 

分 类 号：TL24[核科学技术—核燃料循环与材料]