Magnetic and electronic properties of a Pt-Co bilayer on Pt(111)

Atomically thin Co/Pt(111) interfaces grown at different temperatures are characterized by very different values of perpendicular magnetic anisotropy as a consequence of the local structure and coordination. Here we present a study of the structural, magnetic and electronic properties for interfaces grown in UHV onto clean Pt(111) in different kinetic conditions. When one monolayer of Co is deposited at 540 K a thermally activated exchange reaction leads to a sharp Pt-Co double interface giving rise to a strong increase of the magneto-optical response with respect to the Co monolayer deposited at room temperature. The results are interpreted in terms of atomic hybridization as detected by valence band photoelectron spectroscopy

Probing the surface oxidation of chemically synthesised gold nanospheres and nanorods

In this study, the electrochemical behaviour of commercially available gold spheres and rods stabilised by carboxylic acid and cetyl trimethyl ammonium bromide (CTAB) moieties, respectively, are investigated. The cyclic voltammetric behaviour in acidic electrolyte is distinctly different with the nanorods exhibiting unusual oxidative behaviour due to an electrodissolution process. The nanospheres exhibited responses typical of a highly defective surface which significantly impacted on electrocatalytic activity. A repetitive potential cycling cleaning procedure was also investigated which did not improve the activity of the nanorods and resulted in deactivating the gold spheres due to decreasing the level of surface defects

Surface-sensitive X-ray diffraction across the pressure gap

In this chapter surface-sensitive X-ray diffraction is introduced as an important crystallographic tool for the investigation of surfaces and nanostructures under high pressure reaction conditions and elevated temperatures which are relevant for industrial catalysis. After the introduction surface-sensitive X-ray diffraction methods are briefly explained and specialized instrumentation developed for the in situ investigation of surfaces and nanostructures across the pressure gap is presented combined with simultaneous measurement of the concentrations of reactants and products. In the following an overview of the experimental results is given: First the (near)-ambient pressure oxidation of 3d, 4d, and 5d transition metals is discussed which are relevant for oxidation catalysis. Afterwards catalytic reaction experiments in batch mode are reported, followed by an overview of current research using a flow reactor for surface-sensitive X-ray diffraction. Finally a perspective is given for future research directions