Autocatalysis in the open circuit interaction of alcohol molecules with oxidized Pt surfaces

Author(s)

Batista, Bruno C. ^[1] ; Sitta, Elton ^[1] ; Eiswirth, Markus ^[2] ; Varela, Hamilton ^[1]

Affiliation

^[1] Univ Sao Paulo, Inst Quim Sao Carlos, BR-13560970 Sao Carlos, SP - Brazil

^[2] Max Planck Gesell, Fritz Haber Inst, D-14195 Berlin - Germany

• Document type: Journal article
• Source: Physical Chemistry Chemical Physics; v. 10, n. 44, p. 6686-6692, 2008.
• Web of Science Citations: 16

Abstract

We studied the open circuit interaction of methanol and ethanol with oxidized platinum electrodes using in situ infrared spectroscopy. For methanol, it was found that formic acid is the main species formed in the initial region of the transient and that the steep decrease of the open circuit potential coincides with an explosive increase in the CO(2) production, which is followed by an increase in the coverage of adsorbed CO. For ethanol, acetaldehyde was the main product detected and only traces of dissolved CO(2) and adsorbed CO were found after the steep potential decay. In both cases, the transients were interpreted in terms of (a) the emergence of sub-surface oxygen in the beginning of the transient, where the oxide content is high, and (b) the autocatalytic production of free platinum sites for lower oxide content during the steep decay of the open circuit potential. (AU)

• FAPESP's process: 06/01088-5 - Electrooxidation of ethylene glycol on nickel: kinetics and dynamic instabilities
• Grantee: Elton Fabiano Sitta
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 07/01575-6 - Electrocatalysis using ionic liquids
• Grantee: Bruno Carreira Batista
• Support Opportunities: Scholarships in Brazil - Master