A5057546051- Advancements in Solid Oxide Fuel Cells
- Catalytic Processes in Materials Science
- Nuclear Physics and Applications
- Electrocatalysts for Energy Conversion
- Magnetic and transport properties of perovskites and related materials
- Fuel Cells and Related Materials
- Electronic and Structural Properties of Oxides
- Iron oxide chemistry and applications
- Characterization and Applications of Magnetic Nanoparticles
- Nanomaterials for catalytic reactions
- Magnetic properties of thin films
- X-ray Diffraction in Crystallography
- Gold and Silver Nanoparticles Synthesis and Applications
- Electrochemical Analysis and Applications
- Magnetic Properties and Synthesis of Ferrites
- nanoparticles nucleation surface interactions
- Advanced Condensed Matter Physics
- High-pressure geophysics and materials
- Physics of Superconductivity and Magnetism
- Catalysis and Oxidation Reactions
- Theoretical and Computational Physics
- Atomic and Subatomic Physics Research
- Carbon Nanotubes in Composites
- Inorganic and Organometallic Chemistry
- Organic Electronics and Photovoltaics
Technical University of Denmark
2016-2025
Helmholtz-Zentrum Dresden-Rossendorf
2024
Danish Geotechnical Society
2020
Universität Hamburg
2012
IRD Fuel Cells (Denmark)
2010
Ørsted (Denmark)
2000-2007
Nordic Laboratory for Luminescence Dating
2001-2006
Centre for Sustainable Energy
2003-2005
KU Leuven
1999-2001
University of Copenhagen
1998
Colloidal platinum nanoparticles are obtained via a surfactant-free polyol process in alkaline ethylene glycol. In this popular synthesis, glycol functions as solvent and reducing agent. The preparation procedure is known for its reproducibility to obtain 1–2 nm nanoparticles, but at the same time controlled of larger challenging. A reliable size control without use surfactants fundamental yet missing achievement systematic investigations. work it demonstrated how molar ratio between NaOH...
Carbon-supported Pt-based nanoparticles are important electrocatalysts for energy conversion reactions such as the oxygen reduction reaction (ORR). Although this has been extensively studied, influence of factors particle size and interparticle distance nanoparticle-based or nanosized on ORR activity durability not yet fully understood often intertwined. This lack understanding is mostly based limitation in synthetic approaches electrocatalysts, which usually do allow an independent...
Gold nanoparticles (Au NPs) and gold-based nanomaterials combine unique properties relevant for medicine, imaging, optics, sensing, catalysis, energy conversion. While the Turkevich-Frens Brust-Schiffrin methods remain state-of-the-art colloidal syntheses of Au NPs, there is a need more sustainable tractable synthetic strategies leading to new model systems. In particular, stabilizers are almost systematically used in syntheses, but they can be detrimental fundamental applied studies. Here,...
We present studies of the structural and magnetic properties core–shell iron–iron oxide nanoparticles. α-Fe nanoparticles were fabricated by sputtering subsequently covered with a protective nanocrystalline shell consisting either maghaemite (γ-Fe2O3) or partially oxidized magnetite (Fe3O4). observed that stable against further oxidation, Mössbauer spectroscopy at high applied fields low temperatures revealed form partly magnetite. The structure results in strong canting spin shell, which...
Abstract Compared to conventional preparation methods for supported heterogeneous catalysts, the use of colloidal nanoparticles (NPs) allows a precise control over size, size distribution, and distribution/location NPs on support. However, common syntheses have restrictions that limit their applicability industrial catalyst preparation. We present simple, surfactant‐free, scalable method overcome these restrictions. demonstrate how precious‐metal are prepared in alkaline methanol, particle...
Iridium nanoparticles are important catalysts for several chemical and energy conversion reactions. Studies of iridium have also been a key the development kinetic models nanomaterial formation. However, compared to other metals such as gold or platinum, knowledge on nature prenucleation species structural insights into resultant missing, especially obtained from IrxCly precursors investigated here. We use in situ X-ray total scattering (TS) experiments with pair distribution function (PDF)...
We investigated the cluster-surface interaction of Au clusters deposited on MgO cubes and amorphous carbon, its influence morphology cluster. clusters, produced in a laser vaporization source, are with low energy carbon-coated microscope grids which first as substrates. Clusters carbon well studied by high-resolution electron microscopy (HREM). The have different morphologies for two surfaces, dilation lattice is also measured crystalline surface to perfectly accommodate lattice. Classical...
Abstract Understanding the formation of nanoparticles (NPs) is key to develop materials by sustainable routes. The Co4Cat TM process a new synthesis precious metal NPs in alkaline mono‐alcohols well‐suited active nanocatalysts. ‘facile’, surfactant‐free and performed under mild conditions like low temperature. reducing properties solvent are here shown strongly influence Pt NPs. Based on situ CO adsorbed NP surface oxidation, model proposed that accounts for different growth stabilization...
The Co4Cat approach is a surfactant-free industry-relevant method to synthesize precious metal nanoparticles with enhanced catalytic properties. Colloidal are obtained by reduction of salt in monoalcohol such as methanol the presence base. As opposed alternative syntheses, approach, nature alkali cations used strongly influences most suitable strategy achieve different nanoparticle size, process and stabilize platinum nanoparticles. rational selection base needed detailed here. Monovalent...
The recently reported Co4Cat process is a synthesis method bearing ecological and economic benefits to prepare precious-metal nanoparticles (NPs) with optimized catalytic properties. In the process, metal precursor (e.g., H2 PtCl6 ) dissolved in an alkaline solution of low-boiling-point solvent (methanol) reduced NPs at low temperature (<80 °C) without use surfactants. Here, Pt described detail. advantages this new for research development but also industrial production are highlighted...
Abstract Energy‐efficient, safe, and reliable Li‐ion batteries (LIBs) are required for a wide range of applications. The introduction ultra‐thick graphite anodes, desired high energy densities, meets limitations in internal electrode transport properties, leading to detrimental consequences. Yet, there is lack experimental tools capable providing complete view local processes. Here, multi‐modal operando measurement approach introduced, enabling quantitative spatio‐temporal observations Li...
BackgroundMeteorites originating from Mars represent the only tangible samples that allow us to investigate geologic history of this planet, including its potential early habitability. The discovery polymict regolith breccia NWA 7034 meteorite and pairs, informally known as Black Beauty, provides, for first time, a direct time window into earliest crustal processes on [1,2]. Analyses fragments indicates water was present Martian surface 4450 million years ago [3].Neutron tomographic imaging...
We show that antiferromagnetic nanoparticles of $\ensuremath{\alpha}\text{\ensuremath{-}}{\mathrm{Fe}}_{2}{\mathrm{O}}_{3}$ (hematite) under wet conditions can attach into chains along a common [001] axis. Electron microscopy shows such typically consist two to five particles. X-ray and neutron diffraction studies both structural magnetic correlations exist across the interfaces direction. This gives direct evidence for exchange coupling between Exchange suppress superparamagnetic relaxation...
A simple and high-sensitivity differential scanning calorimeter (DSC) unit operating under magnetic field has been built for indirect determination of the magnetocaloric effect. The principle measuring in is based on Peltier elements as heat flow sensors. high sensitivity apparatus combined with a suitable calibration procedure allows very fast accurate capacity measurements to be made. device was validated from typical DSC reference material gallium (Ga) La0.67Ca0.33MnO3 manganite system...
The combination of self-assembly (bottom up) and nano-imprint lithography (top down) is an efficient effective way to record information at the nanoscale by writing.The use electron beam for writing quite a promising strategy; however, 'paper' on which save not yet fully realized.Herein, graphene was selected as thinnest paper recording nanoscale.In transmission microscope, in situ high precision drawing were achieved nanosheets manipulating electrons with 1 nm probe (probe current ∼2 × 10...
Through the use of Time-of-Flight Three Dimensional Polarimetric Neutron Tomography (ToF 3DPNT) we have for first time successfully demonstrated a technique capable measuring and reconstructing three dimensional magnetic field strengths directions unobtrusively non-destructively with potential to probe interior bulk samples which is not amenable otherwise. Using pioneering polarimetric set-up ToF neutron instrumentation in combination newly developed tailored reconstruction algorithm,...
The controlled synthesis of surfactant-free nanoparticles (NPs) remains a challenge. To develop improved and reproducible syntheses, deeper understanding the formation mechanism NP is key. Pt NPs in particular are important catalysts for wide range applications. In situ X-ray absorption near edge structure (XANES) spectroscopy, small angle scattering (SAXS) transmission electron microscopy (TEM) used to study alkaline ethylene glycol. For first time, different concentrations H2PtCl6 (4 mM or...
Au-Cu bimetallic alloy clusters are produced in a laser vaporization source starting from targets with different stoichiometric compositions. The deposited on two substrates---amorphous carbon and crystalline MgO---and characterized by electron diffraction high-resolution microscopy. experiments show that the overall chemical composition is same as of target material; but crystal structure differs their known bulk structure. Electron microscopy provide evidence no ordering exists between Au...