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oa The Platinised Platinum Interface Under Cathodic Polarisation
MORPHOLOGY CHANGES UNDER THE INFLUENCE OF TETRALKYLAMMONIUM SALTS IN SUPER-DRY SOLUTION
- Source: Platinum Metals Review, Volume 50, Issue 4, Oct 2006, p. 180 - 193
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- 01 Jan 2006
Abstract
Under the use of super-dry dimethylformamide containing tetraalkylammonium salts (TAAX with X = Cl, Br, I, ClO, BF4, etc.) platinised platinum layers may exhibit a reversible charging process that occurs at quite negative potentials (more negative than –2.2 V vs. saturated calomel electrode (SCE)). The mode of reactivity of the electrolyte and the reversibility of the platinum charging of platinised layers (whatever the type of conducting substrate – gold and glassy carbon can also be used successfully) are discussed in terms of the nature of the salt. After cathodic charge and oxidation by air of samples removed from the cell, a huge change of morphology of the original platinised layer was observed. During repeated reduction/oxidation stages, the original amorphous platinised layer was progressively transformed, with a noticeable swelling of the original layer. This transformation, based essentially on cathodic swelling due to the peculiar reactivity of platinum in the presence of bulky tetraalkylammonium salts, is the precondition for a new kind of platinum interface.