A5048452947- Catalysis and Hydrodesulfurization Studies
- Electrocatalysts for Energy Conversion
- 2D Materials and Applications
- Catalytic Processes in Materials Science
- Machine Learning in Materials Science
- Advanced Electron Microscopy Techniques and Applications
- Thermochemical Biomass Conversion Processes
- Catalysis and Oxidation Reactions
- Corrosion Behavior and Inhibition
- Advanced Materials Characterization Techniques
- Advanced Photocatalysis Techniques
- Electron and X-Ray Spectroscopy Techniques
- Catalysts for Methane Reforming
- Electronic and Structural Properties of Oxides
- Catalysis for Biomass Conversion
- Lignin and Wood Chemistry
- Coal Combustion and Slurry Processing
- Biodiesel Production and Applications
- Nanoporous metals and alloys
- X-ray Diffraction in Crystallography
- Petroleum Processing and Analysis
- Material Properties and Failure Mechanisms
- Chemical Synthesis and Characterization
- Semiconductor materials and interfaces
- Ion-surface interactions and analysis
Haldor Topsoe (Denmark)
2012-2024
Danish Geotechnical Society
2020
University of Copenhagen
2008
Atoms on the edge: The atomic edge structure of industrial-style MoS2 nanocatalysts was imaged using single-atom sensitive electron microscopy (see picture). observed terminations match predictions model catalyst studies and thus address so-called "materials gap" in catalysis.
Abstract The functional properties of transition metal dichalcogenides (TMDs) may be promoted by the inclusion other elements. Here, we studied local stoichiometry single cobalt promoter atoms in an industrial‐style MoS 2 ‐based hydrotreating catalyst. Aberration‐corrected scanning transmission electron microscopy and energy loss spectroscopy show that Co occupy sites at (−100) S edge terminations graphite‐supported nanocrystals Specifically, each atom has four neighboring are arranged a...
Close up: The atomic arrangement of industrial-style MoS2 nanocatalysts can be scrutinized by using single-atom-sensitive electron microscopy (see picture). This technique, which provides an excellent agreement between simulation and experiment, allows element detection in compound materials permits the type concentration catalytically important edge sites to estimated. Detailed facts importance specialist readers are published as "Supporting Information". Such documents peer-reviewed, but...
Transmission electron microscopy (TEM) is used to study growth of MoS2 nanocrystals in situ. The are formed from a submonolayer molybdenum oxide dispersed on an support by sulfidation H2S/H2 atmosphere. From series time-resolved TEM images, it revealed that single-layer form preferentially and multi-layer late the process. images pinpoint step sites can act as nucleation centers for grow along surface. Moreover, reveal layer-by-layer mode homogeneous additional layers onto already...
Zinc containing mixed metal oxides and supported zinc oxide are stable selective methanol synthesis catalysts at temperatures where a subsequent to hydrocarbons reaction can occur directly. This work provides fundamental insights into ZnO-based high temperature catalysts. A pronounced support effect was observed, ZrO2 provided beneficial while SiO2 exerted detrimental compared bulk ZnO. Preparing co-precipitated ZnO-ZrO2 showed that the initial activity correlated with amount of amorphous...
We introduce a tertiary transition metal sulfide nanostructure, Pt-Co-Mo-S, for catalytic hydrodesulfurization (HDS) of sulfur-containing molecules in crude oil distillates with the aim to produce ultra-low sulfur transport fuels. The addition ppm-levels Pt standard industrial Co-Mo-S catalyst boosts HDS activity by up 46%. promotional effect is examined combining atomic-resolution Scanning Transmission Electron Microscopy (STEM), Energy Dispersive X-ray Spectroscopy (EDX), Absorption Near...
Catalytic hydropyrolysis of beech wood was conducted in a fluid bed reactor at 450 °C and total pressure 26 bar. The differences hydrodeoxygenation activity, selectivity, the resulting product compositions between sulfided Mo/MgAl2O4, CoMo/MgAl2O4, NiMo/MgAl2O4 catalysts have been investigated. acidity molybdate species oxide catalyst precursors were characterized with ammonia temperature programmed desorption Raman spectroscopy. spent also extensively by scanning electron microscopy (SEM)...
Abstract Advances in electron microscopy have enabled visualizations of the three-dimensional (3D) atom arrangements nano-scale objects. The observations are, however, prone to electron-beam-induced object alterations, so tracking single atoms space and time becomes key unravel inherent structures properties. Here, we introduce an analytical approach quantitatively account for dynamics 3D atomic-resolution imaging. is showcased a Co-Mo-S nanocrystal by analysis time-resolved in-line...
Catalyst stability and deactivation remain significant hurdles, which hinder the realization of many promising chemical processes. This applies especially for biomass conversion over zeolitic materials, where commonly applied solvothermal conditions adversely affect catalysts. For example, tin-doped zeolite Beta, Sn-Beta, is one materials often used a wide range reactions in liquid phase. Herein, we present insights into Sn-Beta catalysts assess different regeneration procedures. We identify...
Atome am Rande: Die atomaren Kanten des industriellen MoS2-Nanokatalysators wurden durch einzelatomempfindliche Transmissionselektronenmikroskopie abgebildet (siehe Bild). beobachteten Kantenabschlüsse stimmen mit Voraussagen aus Modellstudien überein, und die Ergebnisse tragen dazu bei, „Materiallücke“ in der Katalyse zu schließen.
Reconstruction of the exit wave function is an important route to interpreting high-resolution transmission electron microscopy (HRTEM) images. Here we demonstrate that convolutional neural networks can be used reconstruct from a short focal series HRTEM images, with fidelity comparable conventional reconstruction. We use fully network based on U-Net architecture, and train it simulated waves images graphene-supported molybdenum disulphide (an industrial desulfurization catalyst). then apply...
Abstract The functional properties of transition metal dichalcogenides (TMDs) may be promoted by the inclusion other elements. Here, we studied local stoichiometry single cobalt promoter atoms in an industrial‐style MoS 2 ‐based hydrotreating catalyst. Aberration‐corrected scanning transmission electron microscopy and energy loss spectroscopy show that Co occupy sites at (−100) S edge terminations graphite‐supported nanocrystals Specifically, each atom has four neighboring are arranged a...
Nahaufnahme: Die Anordnung der Atome in industriell genutzten MoS2-Nanokatalysatoren kann elektronenmikroskopisch analysiert werden (siehe Bild). vorgestellte Technik erreicht eine Auflösung einzelner und liefert Ergebnisse, die hervorragend mit den Resultaten aus Simulationen übereinstimmen. Ferner lassen sich Elemente Verbindungen detektieren Konzentrationen von Kantenplätzen abschätzen, für Katalysen Bedeutung sind.
In this work sulfided CoMo/MgAl 2 O 4 catalysts used in fluid bed catalytic hydropyrolysis for the conversion 12of beech wood and wheat straw to liquid fuels were thoroughly characterized by Raman spectroscopy 13 scanning (transmission) electron microscopy together with energy dispersive X-ray spectroscopy.Potassium 14 calcium transferred from catalyst accumulated amounts increased 15 proportionally time on stream (TOS) reached 0.67 0.28 wt.% after 16.2 h, respectively, 16 when was as...
Abstract Molybdenum oxide (5 to 20 wt.%) supported on calcium or strontium hydroxyapatite were investigated as catalysts for selective oxidation of methanol formaldehyde. These both active and selective, with a maximum yield achieved at 95 % conversion 96 selectivity. The main byproducts CO (3.2 %) dimethyl ether (DME, 0.7 %). catalytic performance the was measured up 600 h 350 °C. Compared an industrial iron molybdate catalyst, based deactivated slower. species found be surface layer MoO x...
The synthesis and thermal degradation of MAl4(OH)12SO4·3H2O layered double hydroxides with M = Co2+, Ni2+, Cu2+, Zn2+ ("MAl4-LDH") were investigated by inductively coupled plasma-optical emission spectroscopy, thermogravimetric analysis, powder X-ray diffraction, Rietveld refinement, scanning electron microscopy, tunnel energy-dispersive solid-state 1H 27Al NMR spectroscopy. Following extensive optimization, phase pure CoAl4- NiAl4-LDH obtained, whereas 10-12% unreacted bayerite (Al(OH)3)...
In this work, we investigated the catalytic effect of adding sulfur on Zn/ZSM-5 catalyst for direct conversion ethane to aromatics. We show that continuous addition hydrogen sulfide (H2S) effectively stabilizes zinc, prevents coking and results in a highly selective stable catalyst. Considering high content shale gas resources, these highlight importance investigating catalysts under realistic operating conditions.
S2-basierte Nanokatalysatoren werden zur Hydrodesulfurierung in Ölraffinerien eingesetzt. In der Zuschrift auf S. 10 335 ff. präsentieren Helveg et al. einzelatomempfindliche Transmissionselektronenmikroskopieaufnahmen industriell hergestellter Nanokatalysatoren. Die beobachteten katalytisch wichtigen Kantenabschlüsse stimmen mit Voraussagen aus Modellstudien überein. Bild: P. Møller und Nygaard, Haldor Topsøe A/S.
Extended abstract of a paper presented at Microscopy and Microanalysis 2012 in Phoenix, Arizona, USA, July 29 – August 2, 2012.