title: Autocatalysis in the open circuit interaction of alcohol molecules with oxidized Pt surfaces.
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 CO2 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 CO2 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.
authors.affiliation: Instituto de Química de São Carlos, Universidade de São Paulo, C.P. 780, CEP 13560-970, São Carlos, SP, Brazil.
authors.forename: Bruno C
authors.initials: BC
authors.lastname: Batista
authors.forename: Elton
authors.initials: E
authors.lastname: Sitta
authors.forename: Markus
authors.initials: M
authors.lastname: Eiswirth
authors.forename: Hamilton
authors.initials: H
authors.lastname: Varela
mesh_terms: D000079:Acetaldehyde / Q000737:chemistry; D000327:Adsorption; D002245:Carbon Dioxide / Q000737:chemistry; D002248:Carbon Monoxide / Q000737:chemistry; D002384:Catalysis; D004563:Electrochemistry; D004566:Electrodes; D000431:Ethanol / Q000737:chemistry*; D005561:Formates / Q000737:chemistry; D000432:Methanol / Q000737:chemistry*; D010084:Oxidation-Reduction; D010984:Platinum / Q000737:chemistry*; D013055:Spectrophotometry, Infrared; D013499:Surface Properties
chemical_list: D005561:Formates; C030544:formic acid; D002245:Carbon Dioxide; D000431:Ethanol; D010984:Platinum; D002248:Carbon Monoxide; D000079:Acetaldehyde; D000432:Methanol