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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

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

Texto completo
Autor(es):
Zulke, Alana A. [1] ; Varela, Hamilton [1]
Número total de Autores: 2
Afiliação do(s) autor(es):
[1] Univ Sao Paulo, Inst Chem Sao Carlos, POB 780, BR-13560970 Sao Carlos, SP - Brazil
Número total de Afiliações: 1
Tipo de documento: Artigo Científico
Fonte: SCIENTIFIC REPORTS; v. 6, APR 15 2016.
Citações Web of Science: 5
Resumo

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)

Processo FAPESP: 13/16930-7 - Eletrocatálise V: processos eletrocatalíticos de interconversão entre as energias química e elétrica
Beneficiário:Edson Antonio Ticianelli
Modalidade de apoio: Auxílio à Pesquisa - Temático
Processo FAPESP: 12/21204-0 - Auto-organização temporal na eletro-oxidação de moléculas orgânicas pequenas: efeito da estrutura da superfície, da concentração de água e da temperatura
Beneficiário:Bruno Alarcon Fernandes Previdello
Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
Processo FAPESP: 09/07629-6 - Eletrocatálise IV: aspectos fundamentais e aplicados dos processos eletrocatalíticos, bio-eletrocatálise e instabilidades cinéticas
Beneficiário:Edson Antonio Ticianelli
Modalidade de apoio: Auxílio à Pesquisa - Programa BIOEN - Temático