Electrodeposited PtRu on cryogel carbon-Nafion support 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 CC1 and CC2 with pore-size distribution centered at 6 and 20 nm 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-Nafion support with ca. 100 g cm-2 of Pt displayed a good catalytic activity for methanol oxidation of 85 mA per mg of Pt after 600 s at 492 mV vs. NHE and 60°C in H2SO4 0.1M – 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-Nafion electrodes for methanol oxidation are discussed.