http://nova.newcastle.edu.au/vital/access/services/Feed ${session.getAttribute("locale")} 5 http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:5408 Pulsed cathodic arc and pulsed magnetron sputtered WO₃ thin films were investigated using electron microscopy. It was found that the cathodic arc deposited material consisted of the α-WO₃ phase with a high degree of crystallinity. In contrast, the magnetron sputtered material was highly disordered making it difficult to determine its phase. Electron energy-loss spectroscopy was used to study the oxygen K edge of the films and it was found that the near-edge fine structures of films produced by the two deposition methods differed. The oxygen K-edge near-edge structures for various phases of WO₃ were calculated using two different self-consistent methods. Each phase was found to exhibit a unique oxygen K edge, which would allow different phases of WO₃ to be identified using x-ray absorption spectroscopy or electron energy-loss spectroscopy. Both calculation methods predicted an oxygen K edge for the. γ-WO₃ phase which compared well to previous x-ray absorption spectra. In addition, a close match was found between the oxygen K edges obtained experimentally from the cathodic arc deposited material and that calculated for the α-WO₃ phase. 2011-09-13T00:00:01.830Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:7764 Cu:SAPO-5 and Cu:SAPO-11 were prepared by conventional and hydrothermal ion exchange. Copper incorporation is increased six-fold by hydrothermal ion exchange relative to conventional methods. In all cases, the amount of copper taken up by SAPO-11 is superior to uptake in SAPO-5. Copper is divalent and in tetragonally-distorted octahedral environments in the as-prepared samples independent of the method of incorporation for both systems. The local structures about the metal and the valence states associated with the different steps in the selective catalytic reduction of NOᵪ in the presence of propene (SCR-HC) have been investigated using X-ray absorption spectroscopy (XAS). For both the Cu:SAPO-5 and Cu:SAPO-11 systems, heating in helium partially autoreduces copper(II) to copper(I). Following activation in oxygen, propene causes further reduction to copper(I) in all four samples as shown by the evolution of an intense pre-edge diagnostic feature. XANES analysis reveal this to be characteristic of monomeric linear two coordinate copper(I) species. This is a prime example of a pre-edge peak with such a high intensity being observed in the solid state. This is supported by IR where peaks attributed to bidentate copper were observed for Cu:SAPO-11/HT. For all four samples NOᵪ partially reoxidises the copper(I) formed in the helium and propene steps. Ion exchanged Cu:SAPO-5 and Cu:SAPO-11 exhibit low activity in reducing NOᵪ by propene in an oxygen rich environment. The role of the copper ion during NO adsorption was studied using in situ infra red spectroscopy. The activity of copper exchanged materials is governed by both the degree of reducibility of copper(II) and the ease of reversing the valence states with the structural characteristics of the parent materials playing a crucial role. 2011-05-23T03:00:16.479Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:7712 The adsorption of ʟ-cysteine and ʟ-methionine amino acids on a chiral Cu{5 3 1} surface was investigated with high resolution X-ray photoelectron spectroscopy (XPS) and carbon K-edge near edge X-ray absorption fine structure (NEXAFS) Spectroscopy using synchrotron radiation. XPS shows that at 300 K ʟ-cysteine adsorbs through two oxygen, a nitrogen and a sulfur atom, in a four point ‘quadrangular footprint’, whereas ʟ-methionine adsorbs through only two oxygen and a nitrogen atom in a ‘triangular footprint’. NEXAFS was used to clarify the adsorption geometry of both molecules, which suggests a binding orientation to the top layer and second layer atoms in two different orientations associated with adsorption sites on {1 1 0} and {3 1 1} microfacets of the Cu{5 3 1} surface. 2011-05-12T06:30:36.611Z ]]>