Platinum-Doped CeO2 Thin Film Catalysts Prepared by Magnetron Sputtering

The interaction of Pt with CeO2 layers was investigated by using photoelectron spectroscopy. The 30 nm thick Pt doped CeO2 layers were deposited simultaneously by rf-magnetron sputtering on a Si(001) substrate, multiwall carbon nanotubes (CNTs) supported by a carbon diffusion layer of a polymer membrane fuel cell and on CNTs grown on the silicon wafer by the CVD technique. The synchrotron radiation X-ray photoelectron spectra showed the formation of cerium oxide with completely ionized Pt-2+,Pt-4+ species, and with the Pt2+/Pt4+ ratio strongly dependent on the substrate. The TEM and XRD study showed the Pt2+/Pt4+ ratio is dependent on the film structure.