Carbon-Supported, Selenium-Modified Ruthenium–Molybdenum Catalysts for Oxygen Reduction in Acidic Media

Authors

  • Maxime J.-F. Guinel Dr.,

    1. Department of Materials Science and Engineering, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106-7204 (USA)
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  • Arman Bonakdarpour Dr.,

    1. Department of Chemistry, University of Illinois at Urbana–Champaign, 600 South Mathews Avenue, Urbana, IL 61801 (USA), Fax: (+1) 217-244-8068
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  • Biao Wang Dr.,

    1. Department of Chemistry, University of Illinois at Urbana–Champaign, 600 South Mathews Avenue, Urbana, IL 61801 (USA), Fax: (+1) 217-244-8068
    2. College of Material Science and Engineering, Donghua University, 1882 West Yan-an Road, Shanghai, 200051 (PR China)
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  • Panakkattu K. Babu Dr.,

    1. Department of Chemistry, University of Illinois at Urbana–Champaign, 600 South Mathews Avenue, Urbana, IL 61801 (USA), Fax: (+1) 217-244-8068
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  • Frank Ernst Prof.,

    1. Department of Materials Science and Engineering, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106-7204 (USA)
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  • Nagappan Ramaswamy Dr.,

    1. Department of Chemistry and Chemical Biology, Northeastern University, 360 Huntington Avenue, Boston, MA 02115 (USA)
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  • Sanjeev Mukerjee Prof.,

    1. Department of Chemistry and Chemical Biology, Northeastern University, 360 Huntington Avenue, Boston, MA 02115 (USA)
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  • Andrzej Wieckowski Prof.

    1. Department of Chemistry, University of Illinois at Urbana–Champaign, 600 South Mathews Avenue, Urbana, IL 61801 (USA), Fax: (+1) 217-244-8068
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Abstract

The stability and oxygen reduction activity of two carbon-supported catalyst materials are reported. The catalysts, Se/Ru and Se/(Ru–Mo), were prepared by using a chemical reduction method. The catalyst nanoparticles were evenly dispersed onto globular amorphous carbon supports, and their average size was ca. 2.4 nm. Thermal treatment at 500 °C for 2 h in an inert argon atmosphere resulted in coarsening of the nanoparticles, and also in some decrease of their activity. A gradual reduction of activity was also observed for Se/Ru during potential-cycle experiments. However, the incorporation of small amounts of Mo into the Se/Ru catalysts considerably improved the stability of the catalyst against dissolution. The Mo-containing samples showed excellent oxygen reduction activities even after cycling the potential 1000 times between 0.7 and 0.9 V. Furthermore, they showed excellent fuel-cell behavior. The performance of the Se/Ru catalysts is greatly improved by the addition of small amounts of elemental Mo. Possible mechanisms responsible for the improvement of the activity are discussed.

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