电沉积Pd-Fe合金的溶液热力学分析  

Thermodynamical Analysis of Palladium-Iron Alloy Electrodeposition

作　　者：徐明丽[1] 张正富[1] 杨显万[1] 

机构地区：[1]昆明理工大学材料与冶金工程学院,云南昆明650093

出　　处：《稀有金属》2006年第3期319-323,共5页Chinese Journal of Rare Metals

基　　金：国家自然科学基金(50161002);云南省自然科学青年基金(2001E0007Q);国家人事部2001年度博士后基金的资助

摘　　要：以由主盐FeSO4.7H2O,Pd(NH3)2Cl2和导电盐(NH4)2SO4所组成的溶液体系为研究对象,基于溶液各组成同时处于平衡的热力学原理,通过对Fe-H2O系、Pd-H2O系和Fe-NH4+-H2O系三种体系的热力学分析与计算及其电位-pH图的绘制与分析,对电沉积Pd-Fe合金的溶液进行了较为系统的热力学分析。对三者的电位-pH图进行比较分析的结果表明:Pd2+和Fe2+发生共沉积的区域很大,为Pd-Fe合金发生共沉积的可能性提供了理论依据;在简单的Pd2+和Fe2+水溶液中,二者很难发生共沉积,必须在镀液中添加一定量合适的络合剂才能使Pd2+和Fe2+产生共沉积;由于在Fe-NH4+-H2O系中存在Fe2+与NH3和OH-的络合,使游离Fe2+的浓度变小,其电位-pH图中的腐蚀区域比Fe-H2O系电位-pH图的腐蚀区域稍有扩大,且其腐蚀区中含有Fe2+,∑i=1,2,4Fe(NH3)2+i和∑4Fe(NH3)i2+和∑Fe(OH)j2-j三类水溶物。The system of electrolyte solution made up of main salts FeSO4· 7H20, Pd （NH3）2Cl2 and the conductive salt （NH4）2SO4 was studied. With the thermodynamic analysis and E-pH diagrams for Fe-H20, Pd- H20 and Fe-NH4^＋-H2O, the thermodynamic analysis for electrodepositing Fe-Pd alloy from the solution was systemically carried out. Three E-pH diagrams show that the co-depositing region of Pd^2＋ and Fe^2＋ is very wide. It supports theoretically the possibility of electrodepositing Pd-Fe alloy. But it is quite difficult toco-deposit in a simple solution of Pd^2＋ and Fe^2＋ . In order to get the co-deposition, an appropriate complexable agent must be added into the solution. Because of the complex reaction between Fe^2＋ and NH3, OH in the Fe-NH^4＋-H20 system, the concentration of free Fe^2＋ decreases and the corrosive region in E-pH diagram of the system is slightly wider than that of FeH2O, and the region contains Fe^2＋, ∑Fe（NH3）i^2＋↑,4↑∑Fe（0H）i^2-j↑j=1.

关 键 词：钯铁合金 共沉积 电位-PH图 热力学平衡 

分 类 号：TQ153.2[化学工程—电化学工业]