A5018923244- Anodic Oxide Films and Nanostructures
- Semiconductor materials and devices
- Catalytic Processes in Materials Science
- Corrosion Behavior and Inhibition
- Electrochemical Analysis and Applications
- Electrocatalysts for Energy Conversion
- Electron and X-Ray Spectroscopy Techniques
- Aluminum Alloy Microstructure Properties
- Concrete Corrosion and Durability
- Analytical Chemistry and Sensors
- Hydrogen embrittlement and corrosion behaviors in metals
- Copper-based nanomaterials and applications
- Advancements in Battery Materials
- Welding Techniques and Residual Stresses
- Conducting polymers and applications
- Catalysis and Oxidation Reactions
- Advanced ceramic materials synthesis
- Nanoporous metals and alloys
- Nanomaterials for catalytic reactions
- Ammonia Synthesis and Nitrogen Reduction
- Electronic and Structural Properties of Oxides
- X-ray Spectroscopy and Fluorescence Analysis
- Radioactive element chemistry and processing
- Phase Equilibria and Thermodynamics
- Atmospheric chemistry and aerosols
Deutsches Elektronen-Synchrotron DESY
2019-2022
Justus-Liebig-Universität Gießen
2019-2022
Norsk Hydro (Sweden)
2020
Giessen School of Theology
2020
Lund University
2014-2019
John Wiley & Sons (United States)
2019
Interface (United Kingdom)
2019
National Synchrotron Radiation Research Center
2017
Abstract Passivity determines corrosion resistance and stability of highly-alloyed stainless steels, passivity breakdown is commonly believed to occur at a fixed potential due formation dissolution Cr(VI) species. In this work, the study 25Cr–7Ni super duplex steel in 1 M NaCl solution revealed that continuous degradation progress passive film over range, associated with enhanced Fe before rapid Cr removal oxide. The involves structural compositional changes underlying alloy surface layer,...
Sophisticated IrO2(110)-based model electrodes are prepared by deposition of a 10 nm thick single-crystalline IrO2(110) layer supported on structure-directing RuO2(110)/Ru(0001) template, exposing regular array mesoscopic rooflike structures. With this electrode together with the dedicated in situ synchrotron based techniques (SXRD, XRR) and ex characterization (SEM, ToF-SIMS, XPS), corrosion process an acidic environment (pH 0.4) is studied different length scales. Potential-induced pitting...
Abstract Visualizing and measuring the gas distribution in close proximity to a working catalyst is crucial for understanding how catalytic activity depends on structure of catalyst. However, existing methods are not able fully determine during process. Here we report reaction can be imaged situ with high spatial (400 μm) temporal (15 μs) resolution using infrared planar laser-induced fluorescence. The technique demonstrated by monitoring, real-time, carbon dioxide oxidation monoxide above...
We have developed an electrochemical cell for in situ 2-Dimensional Surface Optical Reflectance (2D-SOR) studies during anodization and cyclic voltammetry. The 2D-SOR signal was recorded from electrodes made of polycrystalline Al, Au(111), Pt(100) single crystals. changes can be followed at a video rate acquisition frequency 200 Hz demonstrate strong contrast between oxidizing reducing conditions. Good correlation the conditions or voltammetry current is also observed. power this approach...
The effect of surface strain on the passive film evolution SAF 2507 super duplex stainless steel exposed to ambient air and 0.1 M NaCl solution with varying anodic polarization at room temperature has been investigated using in-situ grazing incidence X-ray diffraction (GIXRD) in combination electrochemical measurements. Surface affected crystallinity as such that oxides/hydroxides were predominantly amorphous, some minor crystalline CrOOH FeOOH present film. Crystalline was seen diminish...
The anodic oxidation of metals such as aluminum and titanium can lead to the development self-ordering pores. These pores make excellent templates for a range nanoscale objects with many applications in nanoscience. Theoretical studies on pore formation have proposed several models establishment, growth, ordering these pores; however, experimental verification has mostly been limited ex situ measurements. Here we show that lateral vertical structure be probed high precision, using grazing...
Self-ordered porous anodic alumina (PAA) films are studied extensively due to a large number of possible applications in nanotechnology and low cost production. Whereas empirical relationships between growth conditions produced oxides have been established, fundamental aspects regarding pore formation self-organization still under debate. We present situ structural studies PAA using grazing-incidence transmission small-angle X-ray scattering. considered the two most used recipes where pores...
We present results from the anodization of an aluminum single crystal [Al(111)] and alloy [Al 6060] studied by in situ x-ray reflectivity, electrochemical impedance spectroscopy ex scanning electron microscopy. For both samples, a linear increase oxide film thickness with increasing voltage was found. However, slope is much higher case, break-up grown on occurs at lower potential than crystal. The reasons for these observations are discussed as measured differences observed reflectivity spectroscopy.
Porous anodic alumina (PAA) can be used as a template for controlled electrodeposition and growth of nanostructures; it is also essential long-lasting decorative coloring aluminum. We have investigated the deposition Sn nanopillars into PAA in situ, with grazing transmission small-angle X-ray scattering, fluorescence, absorption near edge structure spectroscopy. An accumulation could detected pores during electrodeposition. From spectroscopy measurements we conclude that deposited was...
Down to a cathodic potentials of −1.20 V versus the reversible hydrogen electrode, structure IrO2(110) electrodes supported by TiO2(110) is found be stable in situ synchrotron-based X-ray diffraction. Such high should lead reduction metallic Ir (Pourbaix diagram). From IrO2 lattice parameters, determined during polarization H2SO4 electrolyte solution (pH 0.4), it estimated that unit cell volume increases 1% due likely proton incorporation, which lack significant swelling film derived from...
An easy-to-use sample environment reaction cell for X-ray based in situ studies of powders and small structured samples, e.g., powder, pellet, monolith catalysts, is described. The design the allows flexible use appropriate transparent windows, shielding from ambient conditions, such that incident energies as low 3 keV can be used. Thus, absorption spectroscopy (XAS) measurements either transmission or fluorescence mode are facilitated. Total gas flows up to about 500 mln/min fed while...
Using a micro-focused high-energy X-ray beam, we have performed in situ time-resolved depth profiling during the electrochemical deposition of Sn into an ordered porous anodic alumina template. Combined with micro-diffraction are able to follow variation structure at atomic scale as function and time. We show that initially deposits bottom pores, forms metallic nanopillars preferred [100] orientation relatively low mosaicity. The lattice strain is found differ from previous ex measurements...
X-ray photoelectron emission microscopy (XPEEM) was used in combination with other microscopic and spectroscopic techniques to follow the surface development of an aluminum brazing sheet during heating. The studied alloy is a composite material designed for vacuum brazing. Its covered native oxide film. Changes chemical state alloying elements composition layer were detected heating melting temperature. It found that Mg segregates upon heating, measurements indicate formation magnesium...
We report on the influence of oxygen partial pressure for development surface oxides covering industrial aluminum alloy standard 6063 at temperatures ranging from room temperature to 500° C. Using an array synchrotron‐based techniques, we followed change in oxide thickness, chemical composition, and lateral distribution alloying elements. The impact potential is most visible high where composition changes mostly Al based Mg based. This stark contrast ultra‐high vacuum (UHV) conditions only a...
In situ stability studies of an IrO2(110)–TiO2(110) model electrode are carried out under acidic water electrolysis conditions, employing synchrotron-based techniques including surface X-ray diffraction (SXRD) and reflectometry (XRR) with a photon energy 21.5 keV. These experiments complemented by ex scanning electron microscopy (SEM), tunneling (STM), photoelectron spectroscopy (XPS) experiments. Even at anodic current density 250 mA·cm–2 during electrochemical splitting, the turned to be...
We study the structure–function relationship of Pt/Al<sub>2</sub>O<sub>3</sub> during formation ammonia <italic>via in situ</italic> analysis techniques.
In an attempt to bridge the pressure gap, APXPS was used follow surface development of aluminum brazing sheet during heating in ambient oxygen-pressure mimicking environment industrial furnace.The studied alloy is a composite material consisting two standards whose covered with native oxide film.To emphasize necessity studies this system sample environments it compared measurements UHV.Changes thickness and composition were followed after 300 • C, 400 500 C. The sets presented paper show...
We investigate with in situ surface X-ray diffraction (SXRD) and reflectivity (XRR) experiments the cathodic stability of an ultrathin single-crystalline IrO2(110) film a regular array mesoscopic rooflike structures that is supported on RuO2(110)/Ru(0001) template. It turns out planarity lost oxide domains delaminate at potential -0.18 V. Obviously, electrolyte solution able to reach RuO2(110) layer presumably through grain boundaries layer. Subsequently, structure-directing template reduced...
Metal-liquid interfaces are of the utmost importance in a number scientific areas, including electrochemistry and catalysis. However, complicated analytical methods sample preparation usually required to study interfacial phenomena. We propose an infrared spectroscopic approach that enables investigating molecular interactions at interface, but needing only minimal or no preparation. For this purpose, internal reflection element (IRE) is wetted with solution as first step. Second, small...