氯化物熔盐中Nd^(3+)在液体Ga电极上还原的电化学行为

ELECTROCHEMICAL BEHAVIOUR OF Nd^3+ REDUCED ON LIQUID Ga ELECTRODE IN MOLTEN CHLORIDE

本文利用循环V-A法(CV)研究了Nd^(3+)在液体Ga电极上还原的电化学反应动力学。结果表明,Nd^(3+)在Ga电极上的还原是分步进行的。第一步在较高的电位扫描速度下为扩散控制的可逆电荷传递反应,即Nd^(3+)+e?Nd^(2+);在电位扫描速度较低时,随后的化学反应为第一步反应的控制步骤,即Nd^(3+)+e?快Nd^(2+)+mCl→慢NdCl_m^(2-m)。第二步为不可逆的电荷传递反应,即沉积的金属Nd与Ga合金化,Nd^(2+)+2e→Nd(Ga)。估算了该反应的标准反应速度常数为7.0×10^(-3)cm/s。

The kinetics of electrochemical reaction of Nd^(3+) reduced on liquid Ga electrode has been studied by cyclic voltammetry (CV) in molten chloride at 1073K. The results show that the reduction of Nd^(3+)? on Ga electrode proceeds in consequent two steps. For the first step, it is found to be a diffusion controlled reversible re- action at higher rate of potential scan, i. c., Nd^(3+)+e=Nd^(2+) and an irreversible rea- ction controlled by following chemical reaction at lower rate, i. c., Nd^(3+)+e?Nd^(2+) +mCl NdCl'_m^(-m). For the second step, alloying reaction of deposited Nd with Ga can be observed and the reaction is found to irreversible, Nd^(2+)+2e→Nd(Ga). The stand- ard rate constant of this reactiin is estimated to be 7.0×10^(-3) cm/s.