A voltammetric and nanogravimetric study of Te underpotential deposition on Pt in perchloric acid medium |
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Authors: | M.C. Santos S.A.S. Machado |
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Affiliation: | Instituto de Química de São Carlos, Universidade de São Paulo C.P. 760, São Carlos, SP 13560 970, Brazil |
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Abstract: | This work describes the study of Te underpotential deposition on Pt in acid media using cyclic voltammetry, rotating ring-disc electrode and electrochemical quartz crystal microbalance techniques. The voltammetric results indicate the presence of two dissolution peaks in the positive scan with a total charge density of 420 μC cm−2. These phenomena are attributed to the deposition of one Te monolayer with the occupancy of two active Pt sites by each ad-atom. This is confirmed by rotating ring-disc electrode results. The electrochemical quartz crystal microbalance (EQCM) experiments yielded the small mass variation of −32 ng cm−2 (while the theoretical one is −140.4 ng cm−2 for a complete Te monolayer). This low value can be attributed to the simultaneous adsorption of water, perchlorate anions and the formation of platinum oxide. |
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Keywords: | Tellurium Adsorption Underpotential deposition Electrochemical quartz crystal microbalance Ad-atoms |
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