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Bozdech S, Biecher Y, Savinova ER, Schuster R, Krischer K, Bonnefont A. Oscillations in an array of bistable microelectrodes coupled through a globally conserved quantity. CHAOS (WOODBURY, N.Y.) 2018; 28:045113. [PMID: 31906625 DOI: 10.1063/1.5022475] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The dynamical behavior of an array of microelectrodes is investigated under controlled current conditions during CO electrooxidation, a bistable electrochemical reaction with an S-shaped negative differential resistance (S-NDR) current-potential curve. Under these conditions, the total current constitutes a globally conserved quantity, thus coupling all microelectrodes globally. Upon increasing the total current, the microelectrodes activate one by one, with a single microelectrode being on its intermediate S-NDR current branch and the other ones being either on their passive or their active branches. When a few coupled microelectrodes are activated, the electrochemical system exhibits spontaneous potential oscillations. Mathematical analysis shows that oscillations arise already in a two group approximation of the dynamics, the two groups consisting of 1 electrode and n - 1 electrodes with n ≥ 3, respectively, with each group being described by a single evolution equation. In this minimal representation, oscillations occur when the single electrode is on the intermediate branch and the larger group is on the active branch.
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Affiliation(s)
- S Bozdech
- Institut de Chimie des Procédés, pour l'Energie, l'Environnement et la Santé, UMR7515, CNRS-Université de Strasbourg, 25 rue Becquerel, 67087 Strasbourg, France
| | - Y Biecher
- Institut de Chimie des Procédés, pour l'Energie, l'Environnement et la Santé, UMR7515, CNRS-Université de Strasbourg, 25 rue Becquerel, 67087 Strasbourg, France
| | - E R Savinova
- Institut de Chimie des Procédés, pour l'Energie, l'Environnement et la Santé, UMR7515, CNRS-Université de Strasbourg, 25 rue Becquerel, 67087 Strasbourg, France
| | - R Schuster
- Institut für Physikalische Chemie, Karlsruher Institute of Technology, Fritz-Haber-Weg 2, 76131 Karlsruhe, Germany
| | - K Krischer
- Physik Department, Technische Universität München, James-Franck-Str. 1, 85748 Garching, Germany
| | - A Bonnefont
- Institut de Chimie de Strasbourg, UMR7177, CNRS-Université de Strasbourg, 4 rue Blaise Pascal, 67070 Strasbourg, France
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Bozdech S, Krischer K, Crespo-Yapur DA, Savinova E, Bonnefont A. 1/f 2 noise in bistable electrocatalytic reactions on mesoscale electrodes. Faraday Discuss 2016; 193:187-205. [PMID: 27711827 DOI: 10.1039/c6fd00115g] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The formation of a self-organized spatial domain during current-controlled CO oxidation, a kinetically bistable reaction, is investigated experimentally and by deterministic simulations as a function of the electrode size and of the supporting electrolyte concentration. Decreasing the microelectrode size leads to the suppression of the spatial instability at the electrode and thus stabilizes the S-NDR branch of the reaction. The critical microelectrode size capable of supporting sustained domain formation is shown to be strongly affected by the sulfuric acid concentration, the characteristic time of the positive feedback loop increasing with the sulfate concentration. Furthermore, we demonstrate that for microelectrode diameters close to the instability threshold, small amplitude electrochemical potential fluctuations appear in the system. These potential fluctuations cannot be captured by deterministic mathematical models and are attributed to a strong enhancement of molecular fluctuations or intrinsic noise in the vicinity of the spatial instability. Analysis of the electrochemical noise revealed a 1/f 2 frequency dependence and several common features with neuronal shot noise.
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Affiliation(s)
- S Bozdech
- Institut de Chimie et Procédés pour l'Energie, l'Environnement et la Santé, UMR 7515 of CNRS-Université de Strasbourg-ECPM, 25 rue Becquerel, 67087 Strasbourg, France
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Dissipative solitons and backfiring in the electrooxidation of CO on Pt. Sci Rep 2015; 5:16312. [PMID: 26553742 PMCID: PMC4639791 DOI: 10.1038/srep16312] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Accepted: 09/29/2015] [Indexed: 01/08/2023] Open
Abstract
Collisions of excitation pulses in dissipative systems lead usually to their annihilation. In this paper, we report electrochemical experiments exhibiting more complex pulse interaction with collision survival and pulse splitting, phenomena that have rarely been observed experimentally and are only poorly understood theoretically. Using spatially resolved in-situ Fourier transform infrared spectroscopy (FTIR) in the attenuated total reflection configuration, we monitored reaction pulses during the electrochemical oxidation of CO on Pt thin film electrodes in a flow cell. The system forms quasi-1d pulses that align parallel to the flow and propagate perpendicular to it. The pulses split once in a while, generating a second solitary wave in the backward moving direction. Upon collision, the waves penetrate each other in a soliton-like manner. These unusual pulse dynamics could be reproduced with a 3-component reaction-diffusion-migration model with two inhibitor species, one of them exhibiting a long-range spatial coupling. The simulations shed light on existence criteria of such dissipative solitons.
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Pototskaya VV, Gichan OI. Role of ohmic losses in appearance of dynamic instabilities in model electrochemical system with cylindrical electrode under potentiostatic conditions. RUSS J ELECTROCHEM+ 2014. [DOI: 10.1134/s1023193514110081] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Crespo-Yapur DA, Bonnefont A, Schuster R, Krischer K, Savinova ER. Sequential Activation and Oscillations of Globally Coupled Microelectrodes during a Bistable Reaction. ChemElectroChem 2014. [DOI: 10.1002/celc.201402029] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Kaserer S, Rakousky C, Melke J, Roth C. Design of a reference electrode for high-temperature PEM fuel cells. J APPL ELECTROCHEM 2013. [DOI: 10.1007/s10800-013-0567-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Cooperative Behaviour of Pt Microelectrodes during CO Bulk Electrooxidation. Chemphyschem 2013; 14:1117-21. [DOI: 10.1002/cphc.201300105] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Indexed: 11/07/2022]
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Ferreira GCA, Batista BC, Varela H. Experimental assessment of the sensitiveness of an electrochemical oscillator towards chemical perturbations. PLoS One 2012. [PMID: 23185559 PMCID: PMC3503998 DOI: 10.1371/journal.pone.0050145] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
In this study we address the problem of the response of a (electro)chemical oscillator towards chemical perturbations of different magnitudes. The chemical perturbation was achieved by addition of distinct amounts of trifluoromethanesulfonate (TFMSA), a rather stable and non-specifically adsorbing anion, and the system under investigation was the methanol electro-oxidation reaction under both stationary and oscillatory regimes. Increasing the anion concentration resulted in a decrease in the reaction rates of methanol oxidation and a general decrease in the parameter window where oscillations occurred. Furthermore, the addition of TFMSA was found to decrease the induction period and the total duration of oscillations. The mechanism underlying these observations was derived mathematically and revealed that inhibition in the methanol oxidation through blockage of active sites was found to further accelerate the intrinsic non-stationarity of the unperturbed system. Altogether, the presented results are among the few concerning the experimental assessment of the sensitiveness of an oscillator towards chemical perturbations. The universal nature of the complex chemical oscillator investigated here might be used for reference when studying the dynamics of other less accessible perturbed networks of (bio)chemical reactions.
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Affiliation(s)
- Graziela C. A. Ferreira
- Institute of Chemistry of São Carlos, University of São Paulo, São Carlos, São Paulo, Brazil
| | - Bruno C. Batista
- Institute of Chemistry of São Carlos, University of São Paulo, São Carlos, São Paulo, Brazil
| | - Hamilton Varela
- Institute of Chemistry of São Carlos, University of São Paulo, São Carlos, São Paulo, Brazil
- Ertl Center for Electrochemistry and Catalysis, Gwangju Institute of Science and Technology, Gwangju, South Korea
- * E-mail:
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