On the reduction of ClO4- ions in the course of metal dissolution in HClO4 solutions

The problem of the application of perchloric acid and/or perchlorate supporting electrolyte in electrochemical and corrosion studies is discussed. It is demonstrated that in contrast to the general view in the literature the reduction of perchlorate ions could be an important step in the overall process occurring in the course of spontaneous dissolution of some metals in acid perchlorate medium. It is shown that especially in the case of the dissolution of iron the reduction of ClO4- leading to the formation of Cl- plays a substantial role. Consequently, all interpretations concerning the dissolution of iron in the presence of ClO4- ions should be revisited taking into consideration the possibility of the reduction process. (C) 2002 Elsevier Science Ltd. All rights reserved.