Abstract
This paper describes the effects of varying the Pt to Ru ratio in carbon-supported catalysts for methanol oxidation as a function of temperature. Previously these effects were studied in isolation, but now it is shown that the composition of a given catalyst as a function of temperature is extremely important for its activity towards methanol oxidation. Platinum rich 3:2 atomic ratio catalysts perform better than a 1:1 catalyst at 25 °C, where only Pt is believed to be active towards methanol dehydrogenation, since this process is a highly thermally activated process on Ru sites. This result is reversed at 65 °C, where the 1:1 catalyst displays much higher currents across the entire range of polarization. This may result from methanol dehydrogenation occurring on both Ru and Pt sites at higher temperatures. At an intermediate temperature, 45 °C, the 3:2 catalyst is seen to perform better at lower current values, while the 1:1 catalyst is superior at higher current densities, with the crossover occurring at 62 A g−1. As a consequence, when designing fuel cell catalysts, the composition of the catalyst employed should be tailored with respect to the exact operating conditions, in order to promote optimum fuel cell performance.
Similar content being viewed by others
References
L. Carrette, K.A. Friedrich and U. Stimming, Chem. Phys. Chem. 1 (2000) 162.
L. Carrette, J. Collins, A. Dickinson and U. Stimming, Bunsen-Magazin, Deutsche Bunsen-Gesellschaft fuer Physikalische Chemie (in English) 2 (2000) 27.
T. Schultz, S. Zhou and K. Sundmacher, Chem. Eng. Technol. 24(12) (2001) 1223.
S. Wasmus and A. Küver, J. Electroanal. Chem. 461 (1999) 14.
X. Ren, P. Zelenay, S. Thomas, J. Davey and S. Gottesfeld, J. Power Sources 86 (2000) 111.
A.S. Arico, S. Srinivasan and V. Antonucci, Fuel Cells 1 (2001) 133.
G.J.K. Acres, J.C. Frost, G.A. Hards, R.J. Potter, T.R. Ralph, D. Thompsett, G.T. Burstein and G.J. Hutchings, Catal. Today 38(4) (1997) 393.
H.A. Gasteiger, N. Markovic, P.N. Ross, Jr and E.J. Cairns, J. Electrochem. Soc. 141 (1994) 1795.
M. Watanabe and S. Motoo, J. Electroanal. Chem. 60 (1975) 275.
A.K. Shukla, P.A. Christensen, A.J. Dickinson and A. Hamnett, J. Power Sources 76 (1998) 54.
X. Ren, M.S. Wilson and S. Gottesfeld, J. Electrochem. Soc. 143 (1996) L12.
M.K. Ravikumar and A.K. Shukla, J. Electrochem. Soc. 143 (1996) 2601.
P. Argyropoulos, K. Scott and W.M. Taama, Electrochim. Acta 44 (1999) 3575.
A.S. Arico, P.L. Antonucci, E. Modica, A. Baglio, H. Kim and V. Antonucci, Electrochim. Acta 47 (2002) 3723.
T.J. Schmidt, M. Noeske, H.A. Gasteiger and R.J. Behm, J. Electrochem. Soc. 145 (1998) 925.
T.J. Schmidt, H.A. Gasteiger, G.D. Staeb, P.M. Urban, D.M. Kolb and R.J. Behm, J. Electrochem. Soc. 145 (1998) 2354.
T. Iwasita, H. Hoster, A. John-Anacker, W.F. Lin and W. Vielstich, Langmuir 16(2) (2000) 522.
T. Frelink, W. Visscher and J.A.R. van Veen, Surf. Sci. 335 (1995) 353.
T. Frelink, W. Visscher and J.A.R. van Veen, Langmuir 12 (1996) 3702.
Y. Takasu, F. Fujiwara, Y. Murakami, K. Sasaki, M. Oguri, T. Asaki and W. Sugimoto, J. Electrochem. Soc. 147 (2000) 4421.
J.B. Goodenough, R. Manoharan, A.K. Shukla and K.V. Ramesh, Chem. Mater. 1 (1989) 391.
D. Chu and S. Gilman, J. Electrochem. Soc. 143 (1996) 1685.
B. Demishima, H.T. Mishima and G. Castro, Electrochim. Acta 40 (1995) 2491.
C. Lamy, A. Lima, V. LeRhun, F. Delime, C. Coutanceau and J.M. Leger, J. Power Sources 105 (2002) 283.
Z. Jusys, J. Kaiser and R.J. Behm, Electrochim. Acta 47 (2002) 3693.
A.J. Dickinson, L.P.L. Carrette, J.A. Collins, K.A. Friedrich and U. Stimming, Electrochim. Acta 47 (2002) 3733.
A.J. Dickinson, L.P.L. Carrette, J.A. Collins, K.A. Friedrich and U. Stimming, To be published.
K.A. Friedrich, K.P. Geyzers, A.J. Dickinson and U. Stimming, J. Electroanal. Chem. 524–525 (2002) 261.
A.S. Arico, V. Baglio, A. Di Blasi, E. Modica, P.L. Antonucci and V. Antonucci, J. Electroanal. Chem. 557 (2003) 167.
A.K. Shukla, A.S. Arico, K.M. El-Khatib, H. Kim, P.L. Antonucci and V. Antonucci, Appl. Surf. ci. 137 (1999) 20.
A.J. Dickinson, L.P.L. Carrette, J.A. Collins, K.A. Friedrich and U. Stimming, To be published.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Dickinson, A., Carrette, L., Collins, J. et al. Performance of Methanol Oxidation Catalysts with Varying Pt:Ru Ratio as a Function of Temperature. Journal of Applied Electrochemistry 34, 975–980 (2004). https://doi.org/10.1023/B:JACH.0000042668.61391.a4
Issue Date:
DOI: https://doi.org/10.1023/B:JACH.0000042668.61391.a4