A5034793446- Magnetism in coordination complexes
- Catalytic Processes in Materials Science
- Organometallic Complex Synthesis and Catalysis
- Metal complexes synthesis and properties
- Organic and Molecular Conductors Research
- Organometallic Compounds Synthesis and Characterization
- Crystal structures of chemical compounds
- Polyoxometalates: Synthesis and Applications
- Electrocatalysts for Energy Conversion
- Nanocluster Synthesis and Applications
- Inorganic Chemistry and Materials
- Gold and Silver Nanoparticles Synthesis and Applications
- Asymmetric Hydrogenation and Catalysis
- Asymmetric Synthesis and Catalysis
- X-ray Diffraction in Crystallography
- Quantum Dots Synthesis And Properties
- Anodic Oxide Films and Nanostructures
- Inorganic Fluorides and Related Compounds
- Organophosphorus compounds synthesis
- Copper-based nanomaterials and applications
- Metal-Organic Frameworks: Synthesis and Applications
- Cyclopropane Reaction Mechanisms
- Inorganic and Organometallic Chemistry
- Synthesis and characterization of novel inorganic/organometallic compounds
- Pigment Synthesis and Properties
KU Leuven
2015-2024
University of Geneva
2022
Laboratoire de physique des Solides
2011-2020
Utrecht University
2003-2011
University of Amsterdam
2006
Max-Planck-Institut für Kohlenforschung
2005
University of Kent
2001-2005
Institute of Physics
2002
Institute of High Energy Physics
2002
Uppsala University
2002
Unmasking the glow of silver clusters Small stabilized by organic materials or inorganic surfaces can exhibit bright photoluminescence, but origin this effect has been difficult to establish, in part because are heterogeneous and contain many larger inactive clusters. Grandjean et al. studied zeolites, using x-ray excited optical luminescence monitor only emissive structures (see Perspective Quintanilla Liz-Marzán). Aided theoretical calculations, they identified electronic states four-atom...
The hydrothermal crystallization of CoAPO-5 molecular sieves has been studied using time-resolved in-situ SAXS/WAXS, UV−vis, Raman, and XAS. Data collected during heating to 180 °C allowed the observation different steps occurring transformation amorphous gel into a crystalline material from macroscopic atomic perspective. Raman spectroscopy detected initial formation Al−O−P bonds, whereas SAXS showed that these particles had broad size distribution ranging ca. 7 20 nm before began. WAXS...
The effects of the addition manganese to a series TiO2-supported cobalt Fischer−Tropsch (FT) catalysts prepared by different methods were studied combination X-ray diffraction (XRD), temperature-programmed reduction (TPR), transmission electron microscopy (TEM), and in situ absorption fine structure (XAFS) spectroscopy at Co Mn K-edges. After calcination, generally composed large Co3O4 clusters range 15−35 nm MnO2-type phase, which existed either dispersed on TiO2 surface or covering...
The synthesis and characterization of LTA(Li)–Ag zeolites with water-responsive photoluminescence properties high external quantum efficiencies is described in this study.
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDiamagnetic and Paramagnetic Keggin Polyoxometalate Salts Containing 1-D 3-D decamethylferrocenium Networks: Preparation, Crystal Structures Magnetic Properties of [Fe(C5Me5)2]4(POM)(solv)n (POM = [SiMo12O40]4-, [SiW12O40]4-, [PMo12O40]4-, [HFeW12O40]4-; solv H2O, C3H7ON, CH3CN)P. Le Magueres, L. Ouahab, S. Golhen, D. Grandjean, O. Pena, J.-C. Jegaden, C. J. Gomez-Garcia, P. DelhaesCite this: Inorg. Chem. 1994, 33, 23, 5180–5187Publication Date...
The structure and bonding of a series gold clusters nanomaterials stabilized by ligands or confined within nanoporous alumina have been investigated using EXAFS, XANES, WAXS. Two two different ligands, Au55(PPh3)12Cl6 Au55(T8-OSS−SH)12Cl6, were confirmed to be face-centered cubic type with metal−metal distances 2.785 2.794 Å, respectively, shorter than in bulk gold. Colloidal 180 Å diameter sulfonated phosphine had structural electronic properties very similar those but smaller Debye−Waller...
We report the formation of luminescent silver clusters in zeolites by a fast, highly accurate, and controlled activation ions entrapped sodalite cages LTA FAU using high-brilliance soft X-rays. The activated samples were investigated employing combination stationary time-resolved spectroscopic techniques.
A remarkable composition-dependent chemical ordering in Au<sub>x</sub>Ag<sub>1−x</sub> nanoparticles is unravelled experimentally and explained by a four-step growth mechanism.
Unraveling reversible opto-structural switching of few atom luminescent silver clusters confined in LTA zeolites by combination spectroscopic techniques.
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPreparations, x-ray crystal structures, EH band calculations, and physical properties of [(TTF)6(H)(XM12O40)(Et4N)] (M = tungsten, molybdenum; X phosphorus, silicon): evidence electron transfer between organic donors polyoxometalatesL. Ouahab, M. Bencharif, A. Mhanni, D. Pelloquin, J. F. Halet, O. Pena, Padiou, Grandjean, C. Garrigou-Lagrange, Cite this: Chem. Mater. 1992, 4, 3, 666–674Publication Date (Print):May 1, 1992Publication History...
Inert gas condensation (IGC) has been employed to produce nanoparticles of the low-temperature combustion catalyst CuOx/CeO2. For first time we have used a multiple heating crucible setup tailor various morphologies over whole compositional range (2−98% Cu). The factors that control growth, structure, and morphology nanocomposite studied. A powerful combination complementary characterization methods elucidate catalytic synergistics this material. Investigations by high-resolution...
In situ X-ray absorption spectroscopy XAFS at the Cu and Zn K-edge has been used to unravel Cu/Zn interaction identify possible active site of Cu-based methanol synthesis catalysts in Cu/ZnO/SiO2 ternary system. These highly dispersed silica supported catalysts, whose activity increases sharply as a function reduction temperature, were studied calcined, reduced 200, 300, 400 °C, for each temperature under passivation/rereduction conditions. Results showed that calcined form consists mainly...
Platinum is the most active anode and cathode catalyst in next-generation fuel cells using methanol as liquid source of hydrogen. Its catalytic activity can be significantly improved by alloying with 3d metals, although a precise tuning its surface architecture still required. Herein, we report design highly low-temperature (below 0 °C) dehydrogenation reduced CO poisoning based on ultralow amount precisely defined PtxNi1–x (x = to 1) bimetallic clusters (BCs) deposited inert flat oxides...
STEM-EELS and EXAFS have been used to investigate the location electronic state of Mn as promoter in TiO2-supported cobalt Fischer–Tropsch catalysts prepared by two different procedures. It was found that extent interaction between active Co phase well level dispersion over TiO2 surface largely determine enhancement selectivity synthesis at pressures 1 bar.
The appealing luminescent properties of Ag-zeolites have been shown to be dependent on the local environment confined silver clusters. Herein, we shed light Ag clusters inside hydrated Linde-type A (LTA) zeolites and relate them nature host framework when expanded compressed by incorporation Li+ cations Ag+ loading. Within this scenario, measure a strong emission color shift in these materials, which directly correlate with fine structure details derived optical luminescence-detected X-ray...
In this study, we applied cluster beam deposition (CBD) as a new approach for fabricating efficient plasmon-based photocatalytic materials. Au nanoclusters (AuNCs) produced in the gas phase were deposited on TiO2 P25-coated silicon wafers with coverage ranging from 2 to 8 atomic monolayer (ML) equivalents. Scanning Electron Microscopy (SEM) images of AuNCs modified P25 films show that surface is uniformly covered by remain isolated at low (2 ML, 4 ML) and aggregate higher (8 ML). A clear...
Ag clusters (AgCLs) confined within Na-exchanged Linde type A zeolites are studied by X-ray absorption and steady-state time-resolved photoluminescence spectroscopies in a coordinated effort to elucidate the photophysical properties link them precise cluster structure. The hydrated sodalite cage contains mostly tetrahedral [Ag4(H2O)4] located at center of cages, whereas octahedral Ag6 with zeolite framework oxygen (OF) [Ag6(OF)14] formed upon dehydration. time-dependent density functional...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTImproved transparency-efficiency trade-off in a new class of nonlinear organosilicon compoundsG. Mignani, M. Barzoukas, J. Zyss, G. Soula, F. Balegroune, D. Grandjean, and JosseCite this: Organometallics 1991, 10, 3660–3668Publication Date (Print):October 1, 1991Publication History Published online1 May 2002Published inissue 1 October 1991https://pubs.acs.org/doi/10.1021/om00056a043https://doi.org/10.1021/om00056a043research-articleACS...