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Borohydride oxidation on supported Pd and Pd-alloy nano-electrocatalysts (Pd, Pd-Ir, Pd-Ni, Pd-Au, and Pd-Ag) prepared by a modified Bönneman method has been investigated using cyclic voltammetry (CV), rotating disk electrode (RDE) voltammetry, and single fuel cell test station. Electrochemical parameters, such as Tafel slopes, exchange current densities, oxidation peak potentials, and fuel cell performance, have been determined. The electrochemical parameters impact on the cell performance is considered as important as that of the operating conditions. The influences of temperature, and fuel and oxidant flow rates, on the fuel cell performance were also evaluated. The current density of the borohydride fuel cell increases with increase in temperature for all investigated electrocatalysts. The increase in current density with increase in fuel flow rate was not as high as expected within the investigated flow rate range. This is in a good agreement with RDE results. A fuel cell employing Pd-Ir as the anode catalyst and operated at a cell voltage of 0.5 V, can give a current density of 50 mA cm-2 at 298 K, while the same catalyst and at same cell voltage can give 110 mA cm-2 at 333 K.
borohydride fuel cells, colloidal metals, electrocatalysis.
The authors would like to thank the Natural Science and Engineering Research Council of Canada for their financial support of this work. They would also like to thank Dr. Charles Macdonald (Department of Chemistry and Biochemistry, University of Windsor) for the provision of laboratory facilities for the preparation of the electrocatalysts.
[1] Y. Zhu1, S. Ha, R. Masel, J. Power Sources, 130, 8 (2004).
[2] S. Suda et al., Material Stage, Oct. 10, 1(7), 14 (2001).
[3] (www.kucel.hydrogen.co.jp/1-6).
[4] C. Ponce de Leon, F.C. Walsh, D. Pletcher, D.J. Browning, J.B. Lakeman, J. of Power Sources, 155, 172 (2006).
[5] Z.P. Li, B.H. Liu, K. Arai, S. Suda, J. of Alloys and Compounds, 404-406, 648 (2005).
[6] C. Rice, S. Ha, R. I. Masel, A. Wieckowski, J. Power Sources, 155(2), 299 (2003).
[7] K. Yamada, K. Yasuda, H. Tanaka, Y. Miyazaki, T. Kobayashi, J. Power Sources, 122, 132 (2003).
[8] R. Jasinski, Electrochemical Tech., 391, 40 (1965).
[9] S. C. Amendola, P. Onnerud, M. T. Kelly, P. J. Petillo, S. L. Shap-Goldman, M. Binder, J. Power Sources, 84, 130 (1999).
[10] Z. P. Li, B. H. Liu, K. Arai, S. Suda, J. Electrochem. Soc., 150(2), A868 (2003).
[11] Z. P. Li, B. H. Lin, K. Aria, N. Morigazaki, S. Suda, J. Alloys and Comp., 356-357, 469 (2003).
[12] J. Kim, H. Kim, Y. Kang, M. Song, S. Rajendran, S. Han, D. Jung, J. Lee, J. Electrochem. Soc., 151(7), A1038 (2004).
[13] E. Gyenge M. Atwan, , D. Northwood, J. Electrochem. Soc., 153(1), A150 (2006).
[14] M. H. Atwan, C. L. B. Macdonald, D. O. Northwood, E. L. Gyenge, J. Power Sources, 158(1), 36 (2006).
[15] M. H. Atwan, D. O. Northwood, E. L. Gyenge, Inter. J. Hydrogen Energy, 32(15), 3116 (2007).
[16] M. H. Atwan, D. O. Northwood, E. L. Gyenge, Inter. J. Hydrogen Energy, 33(8), 2126 (2008).
[17] H. Bönneman, W. Brijoux, R. Brinkmann, E. Dinjus, T. Jou?en, B. Korall, Angew. Chem. Int. Engl., 30(10), 1312 (1991).
[18] M. Götz and H. Wendt, Electrochim Acta 43(24), 3637 (1998).
[19] R. Richards, R. Mortel, H. Bonnemann, Fuel Cell Bulletin, 4(37), 7 (2001).
[20] H. Bönneman, private communication, October 16, (2003).
[21] H. Bönneman, U. Endruschat, J. Hormes, G. Kohl, S. Kruse, H. Modrow, R. Mortel, K.S. Nagabhushana, Fuel Cells, 4(3), 297 (2004).
[22] R. I. Masel, Chemical Kinetics and Catalysis, Wiley-Interscience, NY, 689-755, 837-880, 667-743 (2001).
[23] A. Kinjo, Diss. Abstr. B, 29, 3235 (1969), and Chem. Abstr. 71, 18189 (1969).
[24] A.J. Bard, L. Faulkner, “Electrochemical methods”, Wiley, New York, 1980.
[25] M.L. Perry, J. Newman and E.J. Cairns, J. Electrochem. Soc. 145, 5 (1998).
[26] J. O’M. Bockris and S.U. M. Khan, “Surface electrochemistry: A molecular level approach”, Plenum Press, New York, 1993, P. 280-283, 621.
[27] E. Gileadi, “Electrode Kinetics”, VCH, NY, 1993, p. 403-454.
[28] S. H. Jordanov, P. Paunovic. O. Popovski, A. Dimitrov, D. Slavkov, Bull. Chem. Tech. of Macedonia, 23 (2), 101 (2004).
[29] M. H. Atwan, E. L. Gyenge, D. O. Northwood, “Electro-chemical Evaluation of Electro catalysts for Fuel Cell Applications: A Practical Approach”, Invited paper Presented at the International Symposium on Solar-Hydrogen-Fuel Cells-10 (International Materials Research Congress 2006), Cancun, Mexico, August 20-24, 2006.