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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.)

Coupled slow and fast surface dynamics in an electrocatalytic oscillator: Model and simulations

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Nascimento, Melke A. [1, 2] ; Nagao, Raphael [1] ; Eiswirth, Markus [2, 3] ; Varela, Hamilton [1, 2, 3]
Total Authors: 4
[1] Univ Sao Paulo, Inst Chem Sao Carlos, BR-13560970 Sao Carlos, SP - Brazil
[2] Max Planck Gesell, Fritz Haber Inst, Dept Phys Chem, D-14195 Berlin - Germany
[3] GIST, Ertl Ctr Electrochem & Catalysis, Kwangju 500712 - South Korea
Total Affiliations: 3
Document type: Journal article
Source: Journal of Chemical Physics; v. 141, n. 23 DEC 21 2014.
Web of Science Citations: 9

The co-existence of disparate time scales is pervasive in many systems. In particular for surface reactions, it has been shown that the long-term evolution of the core oscillator is decisively influenced by slow surface changes, such as progressing deactivation. Here we present an in-depth numerical investigation of the coupled slow and fast surface dynamics in an electrocatalytic oscillator. The model consists of four nonlinear coupled ordinary differential equations, investigated over a wide parameter range. Besides the conventional bifurcation analysis, the system was studied by means of high-resolution period and Lyapunov diagrams. It was observed that the bifurcation diagram changes considerably as the irreversible surface poisoning evolves, and the oscillatory region shrinks. The qualitative dynamics changes accordingly and the chaotic oscillations are dramatically suppressed. Nevertheless, periodic cascades are preserved in a confined region of the resistance vs. voltage diagram. Numerical results are compared to experiments published earlier and the latter reinterpreted. Finally, the comprehensive description of the time-evolution in the period and Lyapunov diagrams suggests further experimental studies correlating the evolution of the system's dynamics with changes of the catalyst structure. (C) 2014 AIP Publishing LLC. (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: 12/24368-4 - Theoretical study of spatio-temporal behavior in electrochemical systems
Grantee:Melke Augusto do Nascimento
Support type: Scholarships abroad - Research Internship - Post-doctor
FAPESP's process: 12/24152-1 - Complex kinetics in electrochemical systems: mechanisms, stoichiometric network analysis and numerical simulations
Grantee:Hamilton Brandão Varela de Albuquerque
Support type: Scholarships abroad - Research
FAPESP's process: 13/16930-7 - Electrocatalysis V: electrocatalytic processes of chemical and electrical energy interconversion
Grantee:Edson Antonio Ticianelli
Support type: Research Projects - 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
FAPESP's process: 11/10982-0 - Spatio-temporal patterns in electrocatalysis: experiments, modeling and numerical simulations
Grantee:Melke Augusto do Nascimento
Support type: Scholarships in Brazil - Post-Doctorate