A5033802412- Electrocatalysts for Energy Conversion
- Catalytic Processes in Materials Science
- Quasicrystal Structures and Properties
- Fuel Cells and Related Materials
- Electrochemical Analysis and Applications
- Microstructure and mechanical properties
- Gold and Silver Nanoparticles Synthesis and Applications
- Nanocluster Synthesis and Applications
- Advanced Memory and Neural Computing
- nanoparticles nucleation surface interactions
- Catalysts for Methane Reforming
- Advanced Photocatalysis Techniques
- Advanced battery technologies research
- Nanoporous metals and alloys
- Machine Learning in Materials Science
- CO2 Reduction Techniques and Catalysts
- Catalysis and Oxidation Reactions
- Copper-based nanomaterials and applications
- X-ray Diffraction in Crystallography
- Nanoparticles: synthesis and applications
- Nanomaterials for catalytic reactions
- Advanced Materials Characterization Techniques
- Quantum Dots Synthesis And Properties
- Aluminum Alloy Microstructure Properties
- Metallic Glasses and Amorphous Alloys
Ernst Ruska Centre
2016-2025
Forschungszentrum Jülich
2016-2025
Rusk Rehabilitation
2021-2023
Grunberger Diabetes Institute
2014-2021
Stadtwerke Jülich (Germany)
2009-2020
Iowa State University
2008
Ames National Laboratory
2008
Institute of Mathematics, Physics, and Mechanics
2008
Kranj School Centre
2008
We demonstrate how shape selectivity and optimized surface composition result in exceptional oxygen reduction activity of octahedral PtNi nanoparticles (NPs). The alloy octahedra were obtained by utilizing a facile, completely surfactant-free solvothermal synthesis. show that the choice precursor ligands controls shape, while reaction time tunes Pt:Ni composition. 9.5 nm sized reached 10-fold area-specific (~3.14 mA/cm(Pt)(2)) as well an unprecedented Pt mass based (~1.45 A/mg(Pt)) gain over...
Abstract Bimetallic nanoparticles of noble metals are high interest in imaging, biomedical devices, including nanomedicine, and heterogeneous catalysis. Synthesis, properties, characterization, biological practical applicability on the basis platinum group coin Ag Au discussed, also comparison with corresponding monometallic nanoparticles. In addition to parameters that required characterize (mainly size, size distribution, shape, crystallographic nature, surface functionalization, charge),...
Chemical dealloying of Pt binary alloy precursors has emerged as a novel and important preparation process for highly active fuel cell catalysts. Dealloying is selective (electro)chemical leaching less noble metal M from rich precursor material been familiar subject macroscale corrosion technology decades. The atomic processes occurring during the nanoscale materials, however, are virtually unexplored hence poorly understood. Here, we have investigated how morphology intraparticle...
Using aberration-corrected scanning transmission electron microscopy and energy loss spectroscopy line profiles with Ångstrom resolution, we uncover novel core-shell fine structures in a series of catalytically active dealloyed Pt(x)Ni(1-x) nanoparticles, showing the formation unusual near-surface Ni-enriched inner shells. The radial location composition shells were sensitively dependent on initial alloy compositions. We further discuss how these self-organized play key role maintaining...
Morphological shape in chemistry and biology owes its existence to anisotropic growth is closely coupled distinct functionality. Although much known about the principal mechanisms of monometallic shaped nanocrystals, alloy nanocrystals still poorly understood. Using aberration-corrected scanning transmission electron microscopy, we reveal an element-specific mechanism platinum (Pt) bimetallic nano-octahedra where compositional anisotropy couples geometric anisotropy. A Pt-rich phase evolves...
Nanoporosity is a frequently reported phenomenon in bimetallic particle ensembles used as electrocatalysts for the oxygen reduction reaction (ORR) fuel cells. It generally considered favorable characteristic, because it increases catalytically active surface area. However, effect of nanoporosity on intrinsic activity and stability nanoparticle electrocatalyst has remained unclear. Here, we present facile atmosphere-controlled acid leaching technique to control formation Pt-Ni nanoparticles....
Thanks to their remarkably high activity toward oxygen reduction reaction (ORR), platinum-based octahedrally shaped nanoparticles have attracted ever increasing attention in last years. Although activities for ORR catalysts been attained, the practical use is still limited by long-term stability. In this work, we present Rh-doped Pt–Ni octahedral with up 1.14 A mgPt–1 combined improved performance and shape stability compared previous bimetallic particles. The synthesis, electrocatalytic of...
The interface of metal-oxide plays pivotal roles in catalytic reactions, but its function is still not clear. In this study, we report the high activity nanostructured Ru/ceria (Ru-clusters/ceria) ethylene methoxycarbonylation (EMC) reaction absence acid promoter. catalyst offers 92% yield MP with TOF 8666 h–1, which about 2.5 times homogeneous Pd (∼3500 h–1). interfacial Lewis acid–base pair [Ru-O-Ce-Vö], consists acidic Ce-Vö (oxygen vacancy) site and basic oxygen Ru-O-Ce linkage, acts as...
For lignin valorization, simultaneously achieving the efficient cleavage of ether bonds and restraining condensation formed fragments represents a challenge thus far. Herein, we report two-step oxidation–hydrogenation strategy to achieve this goal. In oxidation step, O2/NaNO2/DDQ/NHPI system selectively oxidizes CαH–OH Cα═O within β-O-4 structure. subsequent hydrogenation α-O-4 preoxidized structures are further hydrogenated over NiMo sulfide catalyst, leading Cβ–OPh Cα–OPh bonds. Besides...
The lack of suitable candidate electrolyte materials for practical application limits the development all-solid-state Na-ion batteries.
The shuttling behavior and sluggish conversion kinetics of the intermediate lithium polysulfides (LiPS) represent main obstructions to practical application lithium-sulfur batteries (LSBs). Herein, a 1D π-d conjugated metal-organic framework (MOF), Ni-MOF-1D, is presented as an efficient sulfur host overcome these limitations. Experimental results density functional theory calculations demonstrate that Ni-MOF-1D characterized by remarkable binding strength for trapping soluble LiPS species....
Abstract The shuttling behavior and sluggish conversion kinetics of intermediate lithium polysulfides (LiPS) represent the main obstacles to practical application lithium–sulfur batteries (LSBs). Herein, an innovative sulfur host is proposed, based on iodine‐doped bismuth selenide (I‐Bi 2 Se 3 ), able solve these limitations by immobilizing LiPS catalytically activating redox at cathode. synthesis I‐Bi nanosheets detailed here their morphology, crystal structure, composition are thoroughly....
Bulk samples of Pd41Ni10Cu29P20 glass were tested at constant true stress (20–636MPa) in compression 550, 555, and 565K to study the transition from steady-state creep low deformation-induced softening high stress. In high-stress regime strongly accelerating was observed. All deformation homogeneous. The activation volume 106Å3. isoconfigurational energy 9.03±0.64eV. disordering rate is proportional applied power density (stress×strain rate). process inefficient production free volume.
A two-step synthesis for the preparation of single-phase and nanoparticulate GaPd GaPd(2) by coreduction ionic metal-precursors with LiHBEt(3) in THF without additional stabilizers is described. The leads initially to formation Pd nanoparticles followed a Pd-mediated reduction Ga(3+) on their surfaces, requiring an annealing step. majority intermetallic particles have diameters 3 7 nm GaPd(2), respectively, unexpected narrow size distributions as determined disk centrifuge measurements. been...
Multimetallic shape-controlled nanoparticles offer great opportunities to tune the activity, selectivity, and stability of electrocatalytic surface reactions. However, in many cases, our synthetic control over particle size, composition, shape is limited requiring trial error. Deeper atomic-scale insight formation process would enable more rational syntheses. Here we exemplify this using a family trimetallic PtNiCo nanooctahedra obtained via low-temperature, surfactant-free solvothermal...
Shape-controlled octahedral Pt–Ni alloy nanoparticles exhibit remarkably high activities for the electroreduction of molecular oxygen (oxygen reduction reaction, ORR), which makes them fuel-cell cathode catalysts with exceptional potential. To unfold their full and optimized catalytic activity stability, however, nano-octahedra require post-synthesis thermal treatments, alter surface atomic structure composition crystal facets. Here, we address strive to elucidate underlying chemical...
Abstract The efficiency of polymer electrolyte membrane fuel cells is strongly depending on the electrocatalyst performance, that is, its activity and stability. We have designed a catalyst material combines both, high for decisive cathodic oxygen reduction reaction associated with nanoscale Pt alloys, excellent durability an advanced nanostructured support. Owing to specific large active surface area, shows extraordinary mass values 1.0 A mg −1 . Moreover, retains initial area intrinsic...
Column experiments were conducted with undisturbed loamy sand soil under unsaturated conditions (around 90% saturation degree) to investigate the retention of surfactant stabilized silver nanoparticles (AgNPs) various input concentration (Co), flow velocity, and ionic strength (IS), remobilization AgNPs by changing cation type IS. The mobility in was enhanced decreasing solution IS, increasing rate concentration. Significant retardation AgNP breakthrough hyperexponential profiles (RPs)...