Galvanic displacement reactions between sacrificial oxide layers and metal cations, leading to the formation of secondary oxide layers, have been studied with the aim of collecting new experimental evidence on their mechanism. The study has been carried out by combining electrochemical methods, SEM-EDS and XPS depth profiling. Both porous and compact PbO₂ layers have been used as sacrificial oxides and reacted, in different experiments, with: (i) a single low-valent cation, (ii) two cations in sequential exchange reactions or (iii) two cations simultaneously. The experimental results converged to show (i) a lack of correlation between the reaction driving force and the secondary oxide growth rate, (ii) the incorporation of cations from solution at the secondary oxide/electrolyte interface, (iii) the transport of Pb species through the growing secondary oxide layer and (iv) a major effect of mass transport on the growth rate.

已经研究了牺牲氧化物层与金属阳离子之间的电置换反应，导致形成次级氧化物层，目的是收集有关其机理的新实验证据。该研究是通过结合电化学方法，SEM-EDS和XPS深度剖析进行的。多孔和致密的PbO ₂这些层已被用作牺牲氧化物，并在不同的实验中与以下物质反应：（i）一个低价阳离子；（ii）顺序交换反应中的两个阳离子；或（iii）同时两个阳离子。实验结果趋于一致：（i）反应驱动力与次级氧化物生长速率之间缺乏相关性；（ii）在次级氧化物/电解质界面处溶液中引入的阳离子；（iii）铅物种的迁移通过生长的第二氧化物层和（iv）传质对生长速率的重大影响。