OPEN ACCESS
The Palladium-based electrocatalysts (PdSn and PdPtSn) dispersed on carbon Vulcan were prepared by a borohydride reduction of the corresponding chemicals in a THF solution at 0 °C. These catalysts were characterized by Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), X-ray diffraction (XRD) and electrochemical techniques. The physical characterization showed that the method of synthesis enable the formation of particles with less than 10 nm in size. The evaluation of the catalytic activity towards the oxygen reduction reaction (ORR) was carried out by cyclic voltammetry and rotating disk electrode in a 0.5 M H2SO4 solution with different concentrations of methanol. The presence of methanol improved the catalytic activity of the ORR on the bimetallic PdSn, but insignificant effect was observed toward the ORR on PdPtSn alloy. The performance of the membrane electrode assemblies (MEAs), prepared with dispersed PdPtSn/C as a cathode catalyst in a single direct methanol fuel cell (DMFC) showed a maximum power density of 10 mW cm-2 at 50 ° C.
[1] A. Sarkar, A. Murugan, A. Manthiram, J. Mat. Chemistry, 19, 159 (2009).
[2] X. Wang, N. Kariuki, J.T. Vaughev, J. Goodpaster, R. Kumar, D.J. Myers, J. Electrochem. Soc., 155, B602 (2008).
[3] J.J. Salvador-Pascual, S. Citalán-Cigarroa, O. Solorza-Feria, J. Power Sources, 172, 229 (2007).
[4] J.J. Salvador-Pascual, A. Chávez-Carvayar, O. Solorza-Feria, ECS Transactions, 15, 3 (2008).
[5] R.G. González-Huerta, J.A. Chávez-Carvayar, O. Solorza-Feria, J. Power Sources, 153, 11(2006).
[6] U.A. Paulus, T.J. Schmidt, H.A. Gasteiger and R J. Behm, J. Electroanal. Chem., 495, 134 (2001).
[7] S.K. Zecevic, J.S. Wainright, M.H. Litt, S.L. Gojkovic and R.F. Savinell, J. Electrochem. Soc., 144, 2973 (1997).
[8] K. Suárez-Alcántara, A. Rodríguez-Castellanos, S. Durón-Torres, O. Solorza-Feria, J. Power Sources, 171, 381 (2007).
[9] A. Gebert, N. Mattern, U. Kuehn, J. Eckert and L. Schultz, Intermetallics, 15, 1183 (2007).
[10] N.M. Marcovic, H.A. Gasteiger and P.N. Ross, Jr. J. Phys. Chem., 99, 3411 (1995).
[11] C. Couteanceau, P. Crouigneau, J.M. Léger, C. Lamy, J. Electroanal. Chem., 379, 389 (1994).
[12] S.A. Campbell, R. Parsons, J. Chem. Soc. Faraday Trans., 88, 833 (1992).
[13] H.A. Gasteiger, N. Markovic, P.N. Ross, E.J. Cairns, J. Electrochem. Soc. 141, 1795 (1994).
[14] N.M. Markovic, P.N. Ross, Surf. Sci. Rep. 45, 117 (2002).
[15] L. Birry, C. Brock, x. Xue, R. Macmillan, J. Appl. Electrochem., 39, 347 (2009).
[16] A. Casalegno, R. Marchessi, J. Power Sources, 185, 318 (2008).