ZnCl_2-NH_4Cl溶液中锌配合离子的阴极还原

Cathodic Reduction of Zn Complex Ion in the ZnCl_2-NH_4Cl Electrolyte

采用多种电化学方法探讨了ZnCl2NH4Cl溶液配制液中精炼锌的阴极过程. 结果表明:Zn(II)离子在ZnCl2NH4Cl溶液配制液中阴极还原生成金属锌的电极过程,具有两电荷放电一步完成和电荷转移控制的不可逆电极过程动力学规律,Zn(II)离子在此溶液配制液中主要以[Zn(NH3)4]2+配合离子存在,而直接在阴极放电的配合离子物种是[Zn(NH3)2]2+.

The cathodic reduction process of Zn(II) ion in the ZnCl2NH4Cl electrolytic solution was investigated electrochemically. Experimental results show that the cathodic reduction of zinc ions is featured of two electrons discharging in a step. It is an irreversible electrode process in which the charge transfer is the rate-determining step In the ZnCl2NH4Cl system, the dominant form of zinc ammonium complex ion is [Zn(NH3)4]2+, and the main species of the complex ion directly discharging at cathode is essentially [Zn(NH3)2]2+.