The effect of the alkali metal cation on the electrocatalytic oxidation of formate on platinum

Author(s)

Previdello, Bruno A. F. ^[1] ; Machado, Eduardo G. ^[1] ; Varela, Hamilton ^{[1, 2]}

Affiliation

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

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

• Document type: Journal article
• Source: RSC ADVANCES; v. 4, n. 29, p. 15271-15275, 2014.
• Web of Science Citations: 10

Abstract

Non-covalent interactions between hydrated alkali metal cations and adsorbed oxygenated species on platinum might considerably inhibit some electrocatalytic reactions. We report in this communication the effect exerted by electrolyte alkali metal cations on the electro-oxidation of formate ions on platinum. The system was investigated by means of cyclic voltammetry and chronoamperometry in the presence of an electrolyte containing Li+, Na+, or K+. As already observed for other systems, the general activity towards the electro-oxidation of formate ions was found to increase in the sequence Li+ < Na+ < K+. In addition, we observed that the inhibition caused by smaller cations has a peculiar potential dependence because of the multi-peaked current profile of the electro-oxidation of formate on platinum. In this respect, we have also identified a new effect caused by cation inhibition at intermediate potentials, namely a peak splitting towards the use of smaller cations. Results are discussed in connection with mechanistic aspects of this model system. (AU)

• FAPESP's process: 12/24152-1 - Complex kinetics in electrochemical systems: mechanisms, stoichiometric network analysis and numerical simulations
• Grantee: Hamilton Brandão Varela de Albuquerque
• Support Opportunities: Scholarships abroad - Research
• FAPESP's process: 12/21204-0 - Temporal self-organization in electro-oxidation of small organic molecules: surface structure effect, water concentration and temperature
• Grantee: Bruno Alarcon Fernandes Previdello
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 09/07629-6 - Electrocatalysis IV: fundamental and applied aspects of electrocatalytic processes, bio-electrocatalysis and kinetic instabilities
• Grantee: Edson Antonio Ticianelli
• Support Opportunities: Program for Research on Bioenergy (BIOEN) - Thematic Grants
• FAPESP's process: 12/07313-1 - Electro-oxidation of mixed fuels: kinetical instabilities and mechanism
• Grantee: Eduardo Giangrossi Machado
• Support Opportunities: Scholarships in Brazil - Doctorate