Electrodeposited PtRu on cryogel carbon-Nafion supports for DMFC anodes

For a high catalytic activity of the anodes in DMFC at low noble metal content a fine dispersion of PtRu on carbon supports is required and to this purpose we prepared and investigated high specific surface area cryogel carbons of controlled mesoporosity. Two carbons M and CC2 with pore-size distribution centered at 6 and 20nm were obtained by sol-gel polycondensation of resorcinol and formaldehyde, followed by a freeze-drying procedure, a versatile and low-cost method to provide after pyrolysis carbons of controlled porosity. Electrodeposited PtRu on CC2-Nation support with ca. 100 mu g cm(-2) of Pt displayed a good catalytic activity for methanol oxidation of 85 mA mg(-1) of Pt after 600 s at 492 mV versus NHE and 60 degrees C in H2SO4 0.1 M-CH3OH 0.5 M when the Pt-to-C mass ratio was ca. 10%. The catalytic activity tests and XRD and SEM analyses demonstrated the stability of the prepared electrodes upon catalysis in the time scale of our measurements. Strategies to further increase the catalytic activity of the PtRu/cryogel carbon-Nation electrodes for methanol oxidation are discussed. (c) 2006 Elsevier B.V. All rights reserved.