The discrepancy between higher operating pressures applied in catalytic processes and lower measurement pressures accessible during surface characterization is known in the community as the “pressure gap”. To bridge this gap, new experimental and instrumental methods have been developed such as Ambient Pressure XPS (AP-XPS), which allows the collection of photoelectrons at pressures in the...
Hydrogen is a promising energy carrier for the future, especially for mobile applications. It can be stored safely and reversibly at high volumetric densities in hydrogen storage tanks filled with light metal hydrides. Reactive Hydride Composites (RHCs) are metal hydride mixtures that are very promising hydrogen storage materials due to high hydrogen densities, stability and safety. The...
X-ray absorption spectroscopy (XAS) is nowadays a very established tool to investigate and understand chemical reactions on an atomic level. However, it suffers from particular limitations that hinder for example the identification of metal-reactant interactions in catalytic transformations or the detailed investigation of electronic structures. Nevertheless, hard X-rays are highly...
Electrochemical energy storage beyond lithium is of high relevance for a sustainable energy technology. However, qualitatively new concepts are needed for suitable electrodes, especially in the case of the intercalation of larger monovalent ions like Na+ or K+ or multivalent ions like Mg2+, Ca2+ or Zn2+.
One example for a promising Na-ion battery is presented based on symmetrical...
The pair distribution function (PDF) technique experienced a large revival in recent years in the field of nanomaterials as it is able to access the structure of crystallographically challenging materials. [1] By measuring the total, i.e. the Bragg and diffuse, scattering, a variety of materials comprising liquids, glasses and disordered nanoparticles can structurally be analysed....
After its transformation into a dedicated high brilliance synchrotron source, several efforts have been made to implement the opportunity of time-resolved X-ray absorption spectroscopy (XAS). Thanks to the intense photon beam delivered by a tapered undulator in a wide energy range from about 4-40 keV, a time resolution in the millisecond range appears feasible from theory, needing however...
The search for new concepts and materials for energy related technology has become a demanding branch in materials sciences and one focus has been shifted to Li- and Na-ion batteries for ready storage and use of energy. One bottle-neck is the use of liquid electrolytes, which induce a number of limitations, device failure due to corrosion and dendritic intergrowth between cathode and anode,...
Tailoring the chemical reactivity of nanomaterials at the atomic level is one of the most important challenges in catalysis research. In order to achieve this elusive goal, we must first obtain a fundamental understanding of the structural and chemical properties of these complex systems. In addition, the dynamic nature of the nanostructured films and nanoparticle (NP) catalysts and their...
Oxygen intercalation/deintercalation in Pr2NiO4+δ and Nd2NiO4+δ was followed by in situ neutron powder and single crystal synchrotron diffraction during electrochemical oxidation/reduction, in dedicated reaction cells [1]. For both systems three phases, all showing the same line-width, were identified.
The starting phases, Pr2NiO4.23 and Nd2NiO4.24, considered with an average orthorhombic...
Organic photovoltaics (OPV) have received high attention in recent years as an interesting alternative to conventional solar cells. Recent research efforts focus on enhancing the photovoltaic performance in order to make organic solar cells feasible for industrial purposes. This has led to the development of low band-gap materials with reported power conversion efficiencies surpassing the...
