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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 effect of temperature on the coupled slow and fast dynamics of an electrochemical oscillator

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Author(s):
Zulke, Alana A. [1] ; Varela, Hamilton [1]
Total Authors: 2
Affiliation:
[1] Univ Sao Paulo, Inst Chem Sao Carlos, POB 780, BR-13560970 Sao Carlos, SP - Brazil
Total Affiliations: 1
Document type: Journal article
Source: SCIENTIFIC REPORTS; v. 6, APR 15 2016.
Web of Science Citations: 5
Abstract

The coupling among disparate time-scales is ubiquitous in many chemical and biological systems. We have recently investigated the effect of fast and, long-term, slow dynamics in surface processes underlying some electrocatalytic reactions. Herein we report on the effect of temperature on the coupled slow and fast dynamics of a model system, namely the electro-oxidation of formic acid on platinum studied at five temperatures between 5 and 45 degrees C. The main result was a turning point found at 25 degrees C, which clearly defines two regions for the temperature dependency on the overall kinetics. In addition, the long-term evolution allowed us to compare reaction steps related to fast and slow evolutions. Results were discussed in terms of the key role of PtO species, which chemically couple slow and fast dynamics. In summary we were able to: (a) identify the competition between two reaction steps as responsible for the occurrence of two temperature domains; (b) compare the relative activation energies of these two steps; and (c) suggest the role of a given reaction step on the period-increasing set of reactions involved in the oscillatory dynamics. The introduced methodology could be applied to other systems to uncover the temperature dependence of complex chemical networks. (AU)

FAPESP's process: 13/16930-7 - Electrocatalysis V: electrocatalytic processes of chemical and electrical energy interconversion
Grantee:Edson Antonio Ticianelli
Support Opportunities: Research Projects - Thematic Grants
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