Bistability and Oscillations during Electrooxidation of H2−CO Mixtures on Pt: Modeling and Bifurcation Analysis

Autor: Niliifer Baba, Jan Siegmeier, Katharina Krischer
Rok vydání: 2007
Předmět:
Zdroj: The Journal of Physical Chemistry C. 111:13481-13489
ISSN: 1932-7455
1932-7447
DOI: 10.1021/jp072691s
Popis: A model describing the electrooxidation of H2−CO mixtures on rotating Pt electrodes is presented together with a bifurcation analysis for the main experimental parameters. We discuss dynamic instabilities partly caused by a chemical autocatalysis stemming from the CO subsystem and partly from an electrical autocatalysis with the electrode potential as the essential positive feedback variable. Hence, the system contains two different pairs of activator−inhibitor feedback loops. Depending on the parameters, one of the two interaction schemes is dominant, and we find either a so-called S-NDR or an HN-NDR system. However, there are also parameter regimes where the interplay of both loops gives rise to oscillations, greatly enlarging the dynamically unstable parameter range.
Databáze: OpenAIRE
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