Long-Lasting Oscillations in the Electro-Oxidation of Formic Acid on PtSn Intermetallic Surfaces

Authors

  • Nickson Perini,

    1. Institute of Chemistry of São Carlos, University of São Paulo, P.O. Box 780 ,13560-970, São Carlos, SP (Brazil)
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  • Dr. Bruno C. Batista,

    1. Institute of Chemistry of São Carlos, University of São Paulo, P.O. Box 780 ,13560-970, São Carlos, SP (Brazil)
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  • Prof. Antonio C. D. Angelo,

    1. Electrocatalysis Laboratory, UNESP, CP 473, CEP 17033-360, Bauru, SP (Brazil)
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  • Prof. Irving R. Epstein,

    1. Department of Chemistry and Volen Center for Complex Systems, MS 015, Brandeis University, Waltham, Massachusetts 02454-9110, (USA)
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  • Prof. Hamilton Varela

    Corresponding author
    1. Institute of Chemistry of São Carlos, University of São Paulo, P.O. Box 780 ,13560-970, São Carlos, SP (Brazil)
    2. Fritz Haber Institute of the Max Planck Society, Department of Physical Chemistry, Faradayweg 4–6, 14195 Berlin (Germany)
    • Institute of Chemistry of São Carlos, University of São Paulo, P.O. Box 780 ,13560-970, São Carlos, SP (Brazil)===

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Abstract

Even when in contact with virtually infinite reservoirs, natural and manmade oscillators typically drift in phase space on a time-scale considerably slower than that of the intrinsic oscillator. A ubiquitous example is the inexorable aging process experienced by all living systems. Typical electrocatalytic reactions under oscillatory conditions oscillate for only a few dozen stable cycles due to slow surface poisoning that ultimately results in destruction of the limit cycle. We report the observation of unprecedented long-lasting temporal oscillations in the electro-oxidation of formic acid on an ordered intermetallic PtSn phase. The introduction of Sn substantially increases the catalytic activity and retards the irreversible surface oxidation, which results in the stabilization of more than 2200 oscillatory cycles in about 40 h; a 30–40-fold stabilization with respect to the behavior of pure Pt surfaces. The dynamics were modeled and numerical simulations point to the surface processes underlying the high stability.

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