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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

The Electro-Oxidation of Ethylene Glycol on Platinum over a Wide pH Range: Oscillations and Temperature Effects

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Sitta, Elton [1] ; Nagao, Raphael [1] ; Varela, Hamilton [1]
Total Authors: 3
[1] Univ Sao Paulo, Inst Chem Sao Carlos, BR-13560 Sao Carlos, SP - Brazil
Total Affiliations: 1
Document type: Journal article
Source: PLoS One; v. 8, n. 9 SEP 18 2013.
Web of Science Citations: 9

We report a comprehensive study of the electro-oxidation of ethylene glycol (EG) on platinum with emphasis on the effects exerted by the electrolyte pH, the EG concentration, and temperature, under both regular and oscillatory conditions. We extracted and discussed parameters such as voltammetric activity, reaction orders (with respect to {[}EG]), oscillation's amplitude, frequency and waveform, and the evolution of the mean electrode potential at six pH values from 0 to 14. In addition, we obtained the apparent activation energies under several different conditions. Overall, we observed that increasing the electrolyte pH results in a discontinuous transition in most properties studied under both voltammetric and oscillatory regimes. As a relevant result in this direction, we found that the increase in the reaction order with pH is mediated by a minimum (similar to 0) at pH = 12. Furthermore, the solution pH strongly affects all features investigated, c.f. the considerable increase in the oscillatory frequency and the decrease in the, oscillatory, activation energy as the pH increase. We suggest that adsorbed CO is probably the main surface-blocking species at low pH, and its absence at high pH is likely to be the main reason behind the differences observed. The size of the parameter region investigated and the amount of comparable parameters and properties presented in this study, as well as the discussion that followed illustrate the strategy of combining investigations under conventional and oscillatory regimes of electrocatalytic systems. (AU)

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 type: Program for Research on Bioenergy (BIOEN) - Thematic Grants
FAPESP's process: 09/00153-6 - Spatio-temporal self-organization in electrocatalysis
Grantee:Raphael Nagao de Sousa
Support type: Scholarships in Brazil - Doctorate