Platinum supported on a mixed metal oxide, NbRu y O z (8Nb:1Ru), was evaluated as an electrocatalyst for the ethanol oxidation reaction (EOR) in 0.1 M HClO 4 and 1 M KOH. The support was synthesized from a liquid precursor solution of metal chlorides that was aerosolized and thermally decomposed into a powder via the spray pyrolysis (SP) process. Two samples were of primary interest: 30%Pt deposited onto the support by dry impregnation and 60%Pt as part of the precursor solution that underwent in situ SP Pt dispersion. TEM, SEM, and XRD were used to confirm morphology and deposition of Pt. XPS and XAS studies confirmed elemental distribution and oxidation state of Pt catalyst. In situ IRRAS studies in 0.1 M HClO 4 show that these electrocatalysts are capable of facilitating the complete oxidation pathway of EOR, involving scission of the C-C bond and CO oxidation.

Ruthenium oxide materials were evaluated as possible non-carbon-based supports for fuel cell catalysts. The effects of composition and morphology of ruthenium oxide materials on the conductivity and corrosion stability in the gas-diffusion electrode (GDE) configuration were thoroughly investigated. The compositions of the bulk and surface of three ruthenium oxide materials, along with the surface area and surface morphology, were compared. We have found that all tested ruthenium oxide powders exhibited higher corrosion stability compared to carbon. Full conversion of RuO(2).nH(2)O to the RuO(2) phase by postreduction in a hydrogen atmosphere leads to improved conductivity and corrosion stability.

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In this study, spray pyrolysis was used to produce two mesoporous powders, niobium oxide and niobium oxide with 12% ruthenium (by weight, metal basis, based on precursor mixture), as potential catalytic supports in fuel cells. Niobium oxide and ruthenium-modified niobium oxide powders displayed spherical particle morphology with internal mesoporosity introduced by surfactant templating, providing surface areas as high as 183 and 167 m2/g, respectively, after postprocessing that included an acid etch and calcination. The incorporation of ruthenium into niobium oxide, coupled with appropriate postsynthesis treatment, resulted in a material with electrical resistance that was reduced by roughly 5 orders of magnitude relative to unmodified niobium oxide. The structure and properties of these two materials subject to different postprocessing treatments were extensively characterized, and dynamic factors related to aerosol and subsequent thermal processing of these materials are discussed. Cyclic voltammetry showed that the ruthenium-modified material possessed activity for methanol oxidation in a basic environment.

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