Anode Material for Hydrogen Polymer Membrane Fuel Cell: Pt-CeO2 RF-Sputtered Thin Films

The interaction of Pt with CeO2 layers was investigated using photoelectron spectroscopy. Pt-doped CeO2 layers 30 nm thick were deposited by radio-frequency (rf) magnetron sputtering using a composite CeO2-Pt target on a carbon diffusion layer of micropolymer membrane fuel cell covered by double-wall carbon nanotubes. The laboratory X-ray photoelectron spectroscopy and synchrotron radiation soft X-ray photoemission spectra showed the formation of cerium oxide with completely ionized species Pt-2+,Pt-4+ embedded in the film. A small amount of Pt-0 is present on the film surface only. Hydrogen/air fuel cell activity measurements normalized to the amount of used Pt revealed specific power up to 30 W/mg(Pt). The activity of this material is explained by high activity of embedded Pt-2+,Pt-4+ cations toward H-2 dissociation and formation of protonic hydrogen. Very high specific power and low cost together with planar deposition techniques make the material promising for microfabrication of fuel cells to power mobile systems.