Spatio-temporal self-organization in electrocatalysis

• Grant number: 09/00153-6
• Support type: Scholarships in Brazil - Doctorate
• Effective date (Start): May 01, 2009
• Effective date (End): October 31, 2013
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal researcher: Edson Antonio Ticianelli
• Grantee: Raphael Nagao de Sousa
• Home Institution: Instituto de Química de São Carlos (IQSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil

Abstract

The spontaneous formation of spatio-temporal pattern in reaction-transport systems has becoming a very active research area. Complex behavior in these systems takes place under far from thermodynamic equilibrium conditions and results from the interplay between nonlinear temporal dynamics and transport properties. Due to some properties of lateral information exchange and easy global control, reaction-migration systems at the solid/liquid interface are considered ideal model systems. It is proposed in this project the experimental study of the spatio-temporal dynamic found in the electro-oxidation of small organic molecules of kind C1 over polycrystalline platinum surface. The experiments will be shared in two sections: (a) the effect of second metal (i.e. ruthenium) during the oscillatory kinetic of methanol and (b) the effect of anions trifluoromethanesulphonate (SO3CF3-) and hexafluorophosphate (PF6-) during the electro-oxidation of formic acid. Both experiments will be carried out in aqueous solutions of perchloric acid with temperature and mass control. The key aspects of temporal dynamic of system will be investigated through classical electrochemical techniques followed by infrared spectroscopy in situ. Methods of temporal analysis in nonlinear dynamics will be utilized to system characterization, as attractor reconstruction, Fourier transform, section and Poincaré map. From the spatio-temporal dynamic point of view, the experiments will be carried out with a set of sixty four platinum electrodes kept under global control and in which the individual currents will be be independently followed by means of a multichanel data acquisition system. An anular one-dimentional arrangement will be initially adopted and the dynamic investigated under the influence of negative global coupling.

Scientific publications

(9)

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

RAPHAEL NAGAO; MELKE A. NASCIMENTO; HAMILTON VARELA. APARATO ELETROQUÍMICO PARA SISTEMA DE AQUISIÇÃO DE DADOS MULTICANAL COM RESOLUÇÃO ESPAÇO-TEMPORAL. Química Nova, v. 38, n. 1, p. 136-143, Jan. 2015.

NASCIMENTO, MELKE A.; NAGAO, RAPHAEL; EISWIRTH, MARKUS; VARELA, HAMILTON. Coupled slow and fast surface dynamics in an electrocatalytic oscillator: Model and simulations. Journal of Chemical Physics, v. 141, n. 23 DEC 21 2014. Web of Science Citations: 9.

DELMONDE, M. V. F.; NASCIMENTO, M. A.; NAGAO, R.; CANTANE, D. A.; LIMA, F. H. B.; VARELA, H. Production of Volatile Species during the Oscillatory Electro-oxidation of Small Organic Molecules. Journal of Physical Chemistry C, v. 118, n. 31, p. 17699-17709, AUG 7 2014. Web of Science Citations: 14.

SITTA, ELTON; NAGAO, RAPHAEL; VARELA, HAMILTON. The Electro-Oxidation of Ethylene Glycol on Platinum over a Wide pH Range: Oscillations and Temperature Effects. PLoS One, v. 8, n. 9 SEP 18 2013. Web of Science Citations: 9.

NAGAO, RAPHAEL; CANTANE, DANIEL A.; LIMA, FABIO H. B.; VARELA, HAMILTON. Influence of Anion Adsorption on the Parallel Reaction Pathways in the Oscillatory Electro-oxidation of Methanol. Journal of Physical Chemistry C, v. 117, n. 29, p. 15098-15105, JUL 25 2013. Web of Science Citations: 23.

CABRAL, MURILO F.; NAGAO, RAPHAEL; SITTA, ELTON; EISWIRTH, MARKUS; VARELA, HAMILTON. Mechanistic aspects of the linear stabilization of non-stationary electrochemical oscillations. Physical Chemistry Chemical Physics, v. 15, n. 5, p. 1437-1442, 2013. Web of Science Citations: 20.

NAGAO, RAPHAEL; CANTANE, DANIEL A.; LIMA, FABIO H. B.; VARELA, HAMILTON. The dual pathway in action: decoupling parallel routes for CO2 production during the oscillatory electro-oxidation of methanol. Physical Chemistry Chemical Physics, v. 14, n. 23, p. 8294-8298, 2012. Web of Science Citations: 31.

SANTOS, ADRIANO L.; NAGAO, RAPHAEL; OLIVEIRA, CRISTIANE P.; DE LIMA, ROBERTO B.; VARELA, HAMILTON. The role of HBF4 in electro-catalysis: Arsenic contamination and anion adsorption. JOURNAL OF ELECTROANALYTICAL CHEMISTRY, v. 660, n. 1, p. 147-152, SEP 1 2011. Web of Science Citations: 5.

NAGAO, RAPHAEL; SITTA, ELTON; VARELA, HAMILTON. Stabilizing Nonstationary Electrochemical Time Series. Journal of Physical Chemistry C, v. 114, n. 50, p. 22262-22268, DEC 23 2010. Web of Science Citations: 32.

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

SOUSA, Raphael Nagao de. Elucidation of reaction mechanisms under far from thermodynamic equilibrium regime. 2013. Doctoral Thesis - Universidade de São Paulo (USP). Instituto de Química de São Carlos São Carlos.