Electrocatalysis Studies of Transition-Metal Silicides

A series of transition metal silicides were evaluated as catalysts for the anodic oxidation of hydrogen in acid medium. Overall levels of activity were very low and relative levels of activity were very similar for all the compounds except Cr3Si which showed an activity roughly three times the others. Each of the compounds formed highly irreversible passive films when polarized anodically making them quite stable in acid medium. The usefulness of the compounds as catalyst support materials, however, is hindered by difficulties in obtaining efficient electrodeposition of active metals onto the compounds. The study also revealed that erroneous results can easily be obtained in electrocatalysis studies if care is not taken to exclude all traces of platinum from the test cell as platinum was found to migrate about the cell when platinum counter electrodes were used. (Author)
Summary in French.