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A study is conducted to examine the electro-oxidation of CO on model platinum-tin alloy catalysts by ex-situ electrochemical measurements. A surface redox couple, which is associated with the adsorption/desorption on hydroxide on the Sn sites, is observed at 0.28 V(sub RHE)/0.15V(sub RHE) in H2SO4 electrolyte on both surfaces.

Research was conducted to examine the adsorption of the formate species yielded by dissociative adsorption of formic acid on TiO2(110) using combined Fourier transform reflection-absorption IR spectroscopy and X-ray photoelectron spectroscopy. The method was shown to have the advantages of intrinsic resolution for surface vibrational spectroscopy. The interdependence of the two adsorbed formate species offer an explanation for the complex activity seen for several catalytic reactions of formic acid over titania.

Research was conducted to examine the epitaxial growth of CdTe bilayers electrodeposited onto Au single-crystal surfaces using in situ scanning tunneling microscopy. Alternate reductive underpotential deposition (UPD) of Cd and Te and the electrochemical atomic layer epitaxy method were used to generate the films. Results indicate that the growth of the bilayer is dominated by the requirement to achieve stoichiometry and the initial coverage of the Te UPD layer is of overriding importance during the initial growth phase.

The application of a novel method to the high-throughput synthesis and screening of thin film materials and its application to the discovery of electrocatalysts are reported. The results have displayed an enhancement in activity for a range of PtPd alloy compositions over either of the pure elements and have also demonstrated the potential of the methodology for the discovery and optimization of electrocatalysts for a wide range of applications.

Thermal and chemical treatment of metallo-organic chemical vapor deposition (MOCVD)-prepared Rh and Pd model catalysts, supported on TiO2{110}, lead to the formation of carbon residues that are oxidized to CO at elevated temperatures. Observations are discussed in terms of the mobility of surface oxygen species on TiO2{110}, metal- support interactions, and the effect of Cl incorporation into the Tio2 substrate.

A combinatorial synthetic methodology based on evaporation sources under an ultrahigh vacuum has been used to directly synthesize compositional gradient thin film libraries of the amorphous phases of GeSbTe alloys at room temperature over a wide compositional range. An optical screen is described that allows rapid parallel mapping of the amorphous-to-crystalline phase transition temperature and optical contrast associated with the phase change on such libraries. The results are shown to be consistent with the literature for compositions where published data are available along the Sb2Te3-GeTe tie line. The results reveal a minimum in the crystallization temperature along the Sb2Te3-Ge2Te3 tie line, and the method is able to resolve subsequent cubic-to-hexagonal phase transitions in the GST crystalline phase. HT-XRD has been used to map the phases at sequentially higher temperatures, and the results are reconciled with the literature and trends in crystallization temperatures. The results clearly delineate compositions that crystallize to pure GST phases and those that cocrystallize Te. High-throughput measurement of the resistivity of the amorphous and crystalline phases has allowed the compositional and structural correlation of the resistivity contrast associated with the amorphous-to-crystalline transition, which range from 5-to-8 orders of magnitude for the compositions investigated. The results are discussed in terms of the compromises in the selection of these materials for phase change memory applications and the potential for further exploration through more detailed secondary screening of doped GST or similar classes of phase change materials designed for the demands of future memory devices. [ABSTRACT FROM AUTHOR]

Researchers increasingly recognize that, as with standard supportedheterogeneous catalysts, the activity and selectivity of supported metal electrocatalysts are influenced by particle size, particle structure, and catalyst support. Studies using model supported heterogeneous catalysts have provided information about these effects. Similarly, model electrochemical studies on supported metal electrocatalysts can provide insight into the factors determining catalytic activity. [ABSTRACT FROM AUTHOR]

A study of the lithium ion conductor Li3xLa2/3-xTiO3 solid solution and the surrounding composition space was carried out using a high throughput physical vapor deposition system. An optimum total ionic conductivity value of 5.45 x 10-4 S cm-1 was obtained for the composition Li0.17La0.29Ti0.54 (Li3xLa2/3-xTiO3 x = 0.11). This optimum value was calculated using an artificial neural network model based on the empirical data. Due to the large scale of the data set produced and the complexity of synthesis, informatics tools were required to analyze the data. Partition analysis was carried out to determine the synthetic parameters of importance and their threshold values. Multivariate curve resolution and principal component analysis were applied to the dim-action data set. This analysis enabled the construction of phase distribution diagrams, illustrating both the phases obtained and the compositional zones in which they occur. The synthetic technique presented has Significant advantages over other thin film and bulk methodologies. In terms of both the compositional range covered and the nature of the materials produced. [ABSTRACT FROM AUTHOR]