H_2SO_4-NH_4F-SbF_3体系中锑(Ⅲ)的电沉积机理  

Electrodeposition Mechanism of Antimony(Ⅲ) in H_2SO_4-NH_4F-SbF_3 Electrolyte System

作　　者：林艳[1] 谢刚[1] 杨大锦[2] 

机构地区：[1]昆明理工大学材料与冶金工程学院,昆明650093 [2]云南冶金集团股份有限公司技术中心,昆明650031

出　　处：《有色金属（冶炼部分）》2010年第3期5-9,共5页Nonferrous Metals（Extractive Metallurgy)

基　　金：云南省科技攻关项目资助(2000KFZX-14)

摘　　要：采用循环伏安法和稳态极化法,探讨了H2SO4-NH4F-SbF3体系中三价锑的电沉积机理。研究结果表明:H2SO4-NH4F-SbF3体系中,三价锑的阴极还原为两步进行的不可逆反应,第一步电子转移数为1,第二步电子转移数为2;控制步骤为第一步电子转移步骤;还原反应存在前置转化步骤。通过循环伏安曲线分析,计算得到不同温度下的传递系数α分别为0.130(25℃),0.127(30℃),0.123(35℃),0.123(40℃),0.119(45℃)。通过稳态极化曲线分析,计算得到两步反应的交换电流密度分别为i01,c=286.583和i02,c=1.780×106;表观活化能分别为E1=22.181 kJ/mol和E2=15.752 kJ/mol。通过电化学级数法,确定了电活性品种为SbF2+。The electrodeposition mechanism of antimony（Ⅲ） in H2SO4-NH4F-SbF3 electrolyte system has been investigated by cyclic voltammetry and stable polarization.It is concluded that antimony（Ⅲ） could be reduced to antimony metal via two-steps irreversible electron transfer process in which the electron transfer number of two steps are n1=1 and n2=2.It has also been shown that first electron transfer reaction is the rate controlling step and the trivalent antimony complex undergoes chemical transformation reaction before its reduction in the cathode.The transfer coefficients at various temperatures which are 0.130（25℃）,0.127（30℃）,0.123（35℃）,0.123（40℃）,0.119（45℃）have been calculated respectively by analysis of cyclic voltammetry curve.Analysis results of stable polarization shows that exchange current densitys of two electron transfer steps are i01,c=286.583,i02,c=1.780×106 and the apparent activation energys are E1=22.181 kJ/mol,E2=15.752 kJ/mol.The electro-active complex which is SbF2＋ ions has been determined by electrochemical progression method.

关 键 词：H2SO4-NH4F-SbF3体系 锑 电活性品种 电化学动力学 

分 类 号：TF818[冶金工程—有色金属冶金]