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进行了氨性溶液中Cu置换Ag的热力学分析,计算结果表明,该置换反应在热力学上是可能的。用Cu的旋转圆盘研究了氨性溶液中Cu置换Ag的动力学,观察到有两段反应速率,即初始段反应速率慢和第二段反应速率增快。发现沉积物的形态明显影响置换速率。初始阶段的反应对应于Ag沉积于较光滑的表面,置换动力学受传质控制;第二阶段反应速率增快,是由于形成粗糙结构的表面沉积物,使适于该置换反应进行的表面积有效增加。
The thermodynamic analysis of Cu substitution in ammoniacal solution was carried out. The calculation results show that the substitution reaction is thermodynamically possible. The kinetics of Cu substitution for Ag in ammoniacal solution was investigated by using a rotating disk of Cu. Two reaction rates were observed, namely, the initial reaction rate was slow and the second reaction rate was faster. The morphology of the deposit was found to significantly affect the replacement rate. The reaction at the initial stage corresponds to the deposition of Ag on the smoother surface and the displacement kinetics to be controlled by the mass transfer. The second stage of reaction rate is accelerated by the formation of a rough structured surface deposit that renders the surface area suitable for the displacement reaction effective increase.