论文部分内容阅读
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 of U4 + in LiF-NaF molten salt at 1073K was studied by cyclic voltammetry and chronopotentiometry. The results show that the reduction of U4 + in fluoride melt salt is divided into two steps. The number of reaction electrons in each step is analyzed to determine the U4 + + e = U3 + and U3 + + 3e = U U4 + The peak potentials of the two reduction peaks did not negatively shift with the increase of the sweep rate. The peak current and the square root of the sweep rate showed a good linear relationship, indicating that the two reduction processes were both diffusion controlled and reversible. The calculated 1073K The diffusion coefficient of U4 + in LiF-NaF is DU (IV) = 2.58 × 10-5cm2 / s.