A5078088558- Electron and X-Ray Spectroscopy Techniques
- Advanced Electron Microscopy Techniques and Applications
- Machine Learning in Materials Science
- Advanced Materials Characterization Techniques
- Catalytic Processes in Materials Science
- Electrocatalysts for Energy Conversion
- Catalysis and Oxidation Reactions
- Mesoporous Materials and Catalysis
- Surface and Thin Film Phenomena
- Semiconductor materials and devices
- Ion-surface interactions and analysis
- Force Microscopy Techniques and Applications
- X-ray Diffraction in Crystallography
- Advancements in Battery Materials
- Nanocluster Synthesis and Applications
- Magnetic properties of thin films
- Magnetic and transport properties of perovskites and related materials
- nanoparticles nucleation surface interactions
- Nanomaterials for catalytic reactions
- Advanced Battery Technologies Research
- Carbon Nanotubes in Composites
- Advanced Battery Materials and Technologies
- Crystallization and Solubility Studies
- Fuel Cells and Related Materials
- Nanoporous metals and alloys
Johnson Matthey (United Kingdom)
2012-2024
Diamond Light Source
2019-2024
Johnson Matthey (Germany)
2004-2022
Technology Centre Prague
2004-2022
Johnson Matthey (United States)
2014-2022
Reading Museum
2019-2020
Research Complex at Harwell
2017
University of Oxford
2000-2004
University of Cambridge
1994-2000
Royal Institution of Great Britain
1998
High-performance, bimetallic nanoparticle catalysts (M1+M2) were obtained by gentle thermolysis of their precursor metal-cluster carbonylates physisorbed inside the mesoporous channels silica (the hexagons in figure). The Cu–Ru catalyst anchored on is stable use and has been tested catalytic hydrogenation hex-1-ene, diphenylacetylene, phenylacetylene, stilbene, cis-cyclooctene, D-limonene.
A new hydrogenation catalyst is formed by thermolysis of the anionic carbonyl cluster [Ag3Ru10C2(CO)28Cl]2− anchored to mesoporous silicate MCM-41. The was isolated and characterized in MCM-41 both before after thermal treatment. picture on right shows a model, based particular EXAFS analysis, active bimetallic particle. distribution Ag/Ru particles cavities determined electron microscopy.
Picture perfect: Information about the local topologies of active sites on commercial nanoparticles can be gained with atomic resolution through spherical-aberration-corrected transmission electron microscopy (TEM). A powder Pt carbon black was examined two advanced TEM techniques based recent developments in hardware (aberration correction) and computation (exit wavefunction restoration).
Atom probe tomography (APT) has been used to characterize commercially prepared Pt, Pt/Co alloy, and Ir@Pt core–shell nanoparticles supported on high-surface-area carbon black. Concentration profiles 3D atom maps revealing the detailed internal structures compositions of particles have generated, distribution trace impurity elements, including Na Cl, examined. The observation retained support, especially in Pt nanoparticle system, indicates a more rigorous washing procedure is required. In...
Many studies of heterogeneous catalysis, both experimental and computational, make use idealized structures such as extended surfaces or regular polyhedral nanoparticles. This simplification neglects the morphological diversity in real commercial oxygen reduction reaction (ORR) catalysts used fuel-cell cathodes. Here we introduce an approach that combines 3D nanoparticle obtained from high-throughput high-precision electron microscopy with density functional theory. Discrepancies between...
Significant effects on catalytic activity in the epoxidation of cyclohexene with alkyl hydroperoxides are observed when surface mesoporous silica (MCM-41) is modified either Ge(IV) or Sn(IV) prior to grafting tetracoordinated Ti(IV). Titanium centers attached via oxygen two silicons and one germanium show an increase turnover frequency up 140% compared three Si−O bonds a purely siliceous MCM-41. The tin-modified catalyst, contrast, shows poor activity. environments Ti, Ge, Sn were probed...
The new generation of energy-dispersive X-ray (EDX) detectors with higher count rates than ever before, paves the way for a approach to quantitative elemental analysis in scanning transmission electron microscope. Here we demonstrate method calculating partial cross sections use quantifying EDX data, beneficial especially because simplicity its implementation. Applying this acid-leached PtCo catalyst nanoparticles leads determination Pt surface enrichment.
Abstract We describe nNPipe for the automated analysis of morphologically diverse catalyst materials. Automated imaging routines and direct-electron detectors have enabled collection large data stacks over a wide range sample positions at high temporal resolution. Simultaneously, traditional image approaches are slow hence unsuitable consequently, researchers progressively turned towards machine learning deep approaches. Previous studies often detail work on uniform material systems with...
Summary High‐angle annular dark‐field scanning transmission electron microscopy tomography is applied to the study of Pt and PtCr nanoparticles supported on carbon black, which are used as heterogeneous catalysts in electrodes proton exchange membrane fuel cells. By using tomography, three‐dimensional architecture catalyst system can be determined, providing high‐spatial‐resolution information about shapes, faceting crystallographies 5–20 nm single multiply twinned particles, well their...
To improve the understanding of catalysts, and ultimately ability to design better materials, it is crucial study them during their catalytic active states. Using in situ or operando conditions allows insights into structure-property relationships, which might not be observable by ex characterization. Spatially resolved X-ray fluorescence, diffraction absorption near-edge spectroscopy are powerful tools determine structural electronic properties, spatial resolutions now achievable at hard...
Zn nanowires with an epitaxial thin surface layer of zinc oxide were dispersed onto amorphous carbon films and stored at room temperature. After 1500 h, a self-organized equal-spaced (approximately 2 nm)/carbon 2.5 nm) multilayer structure was found to form outside the nanowire, taking place original ZnO layer. We carried systematic study clarify self-formation mechanism periodical multilayers nanowire out that such configuration originated from chemical reaction between CO2 formed via gas...
Unstable cathode electrolyte interphase (CEI) formation increases degradation in high voltage Li-ion battery materials. Few techniques couple characterization of nano-scale CEI layers on the macroscale with situ chemical characterization, and thus, information how underlying microstructure affects is lost. Here, process a material, LiCoPO4, has been investigated for first time using helium ion microscopy (HIM) time-of-flight (ToF) secondary mass spectrometry (SIMS). The combination HIM...
The novel organometallic cluster polymer of probable formula [Ru6C(CO)15Ph2PC2PPh2 ]n (n = ca. 1000) 1 has been prepared and, on irradiation in an electron beam, forms first nanoparticle chains and then conducting wires.
Bildhübsche Bilder: Informationen zur Umgebung aktiver Zentren auf käuflichen Nanopartikeln werden atomarer Ebene durch Transmissionselektronenmikroskopie (TEM) mit Korrektur für die sphärische Aberration erhalten. Pt-Nanopartikel-Pulver Kohle wurde zwei TEM-Techniken untersucht, jüngste Entwicklungen bei Hardware und Rechenverfahren nutzen.
Small particles with face-centred cubic structures can have non-single-crystallographic shapes. Here, an approach based on annular dark-field scanning transmission electron microscopy (STEM) is used to obtain information about the crystal sub-units that make up supported and unsupported twinned Pt, Pt alloy Au nanoparticles. The three-dimensional shapes of two types lamellar-twinned (LTPs) are obtained using high-angle STEM. Possible growth mechanisms LTPs origins for contrast features in...
Although Pt is extensively used as a catalyst to purify automotive exhaust gas, it desirable reduce consumption through size reduction because rare element and an expensive noble metal. In this study, we successfully loaded
A per layer assessment of nanoparticle strain in Pt<sub>3</sub>Co nanoparticles<italic>via</italic>a combination atomic resolution microscopy and computational modelling.
The properties of the ruthenium nanocluster polymer formula [Ru6C(CO)15P(C6H5)2CCP(C6H5)2]n are studied by atomic-force microscopy, Fourier-transform infrared spectroscopy, and electron microscopy as a function electron-beam exposure. These related to electrical conductivity, which is measured at various temperatures electric fields. A hopping correlation length 240 nm deduced explained on basis formation superclusters in an insulating matrix.