| Full text | |
| Author(s): |
Total Authors: 2
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| Affiliation: | [1] Univ Sao Paulo, Inst Chem Sao Carlos, POB 780, BR-13560970 Sao Carlos, SP - Brazil
Total Affiliations: 1
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| 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 |