Records |
Author |
Leusink, D.P.; Coneri, F.; Hoek, M.; Turner, S.; Idrissi, H.; Van Tendeloo, G.; Hilgenkamp, H. |
Title |
Thin films of the spin ice compound Ho2Ti2O7 |
Type |
A1 Journal article |
Year |
2014 |
Publication |
APL materials |
Abbreviated Journal |
Apl Mater |
Volume |
2 |
Issue |
3 |
Pages |
032101-32107 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
The pyrochlore compounds Ho2Ti2O7 and Dy2Ti2O7 show an exotic form of magnetism called the spin ice state, resulting from the interplay between geometrical frustration and ferromagnetic coupling. A fascinating feature of this state is the appearance of magnetic monopoles as emergent excitations above the degenerate ground state. Over the past years, strong effort has been devoted to the investigation of these monopoles and other properties of the spin ice state in bulk crystals. Here, we report the fabrication of Ho2Ti2O7 thin films using pulsed laser deposition on yttria-stabilized ZrO2 substrates. We investigated the structural properties of these films by X-ray diffraction, scanning transmission electron microscopy, and atomic force microscopy, and the magnetic properties by vibrating sample magnetometry at 2 K. The films not only show a high crystalline quality, but also exhibit the hallmarks of a spin ice: a pronounced magnetic anisotropy and an intermediate plateau in the magnetization along the [111] crystal direction. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000334220300002 |
Publication Date |
2014-03-04 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2166-532X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.335 |
Times cited |
18 |
Open Access |
|
Notes |
The authors acknowledge support from the Dutch FOM and NWO foundations and from the European Union under the Framework 7 program under a contract from an Integrated Infrastructure Initiative (Reference 312483 ESTEEM2). G.V.T. acknowledges the ERC Grant N246791- COUNTATOMS. S.T. gratefully acknowledges financial support from the Fund for Scientific Research Flanders (FWO). H.I. acknowledges the IAP program of the Belgian State Federal Office for Scientific, Technical and Cultural Affairs under Contract No. P7/21. The microscope used in this study was partially financed by the Hercules Foundation of the Flemish Government. The authors acknowledge fruitful interactions with A. Brinkman, M. G. Blamire, M. Egilmez, F. J. G. Roesthuis, J. N. Beukers, C. G. Molenaar, M. Veldhorst, and X. Renshaw Wang; esteem2_ta |
Approved |
Most recent IF: 4.335; 2014 IF: NA |
Call Number |
UA @ lucian @ c:irua:115555 |
Serial |
3641 |
Permanent link to this record |
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|
|
Author |
Geukens, I.; Vermoortele, F.; Meledina, M.; Turner, S.; Van Tendeloo, G.; De Vos, D.E. |
Title |
Ag nanoparticles on mixed Al2O3-Ga2O3 supports as catalysts for the N-alkylation of amines with alcohols |
Type |
A1 Journal article |
Year |
2014 |
Publication |
Applied catalysis : A : general |
Abbreviated Journal |
Appl Catal A-Gen |
Volume |
469 |
Issue |
|
Pages |
373-379 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The combination of AgNO3 with NaH results in Ag nanoparticles that can selectively perform alcohol aminations under mild reaction conditions (110 °C). NaH not only serves as a reducing agent for the Ag salt, but also activates the alcohol for dehydrogenation to the corresponding ketone/aldehyde. The stability of the particles can be improved by immobilizing them onto mixed Al2O3Ga2O3 supports; the combination of Ga and Al provides materials with stronger Lewis acidic sites compared to pure alumina or gallium oxide supports. This leads to catalysts with enhanced activities, without the necessity of adding external Lewis acids. Detailed TEM characterization also reveals a close interaction between the Ag NPs and the gallium oxide phase. The obtained catalysts are recyclable and show activity for the alcohol amination using a variety of aliphatic and aromatic amines under mild conditions. |
Address |
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Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
Language |
|
Wos |
000329266500045 |
Publication Date |
2013-10-10 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0926-860X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.339 |
Times cited |
24 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 4.339; 2014 IF: 3.942 |
Call Number |
UA @ lucian @ c:irua:111095 |
Serial |
83 |
Permanent link to this record |
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|
|
Author |
Zhao, Q.; Lorenz, H.; Turner, S.; Lebedev, O.I.; Van Tendeloo, G.; Rameshan, C.; Klötzer, B.; Konzett, J.; Penner, S. |
Title |
Catalytic characterization of pure SnO2 and GeO2 in methanol steam reforming |
Type |
A1 Journal article |
Year |
2010 |
Publication |
Applied catalysis : A : general |
Abbreviated Journal |
Appl Catal A-Gen |
Volume |
375 |
Issue |
2 |
Pages |
188-195 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Structural changes of a variety of different SnO, SnO2 and GeO2 catalysts upon reduction in hydrogen were correlated with associated catalytic changes in methanol steam reforming. Studied systems include SnO, SnO2 and GeO2 thin film model catalysts prepared by vapour phase deposition and growth on polycrystalline NaCl surfaces and, for comparison, the corresponding pure oxide powder catalysts. Reduction of both the SnO2 thin film and powder at around 673 K in 1 bar hydrogen leads to a substantial reduction of the bulk structure and yields a mixture of SnO2 and metallic β-Sn. On the powder catalyst this transformation is fully reversible upon oxidation in 1 bar O2 at 673 K. Strongly reduced thin films, however, can only be re-transformed to SnO2 if the reduction temperature did not exceed 573 K. For GeO2, the situation is more complex due to its polymorphism. Whereas the tetragonal phase is structurally stable during reduction, oxidation or catalytic reaction, a small part of the hexagonal phase is always transformed into the tetragonal at 673 K independent of the gas phase used. SnO2 is highly active and CO2 selective in methanol steam reforming, but the initial high activity drops considerably upon reduction between 373 and 573 K and almost complete catalyst deactivation is observed after reduction at 673 K, which is associated with the parallel formation of β-Sn. In close correlation to the structural results, the catalytic activity and selectivity can be restored upon an oxidative catalyst regeneration at 673 K. Tetragonal GeO2 exhibits only a small activity and no pronounced selectivity to either CO or CO2, at least after reduction. In its fully oxidized state release of surface/lattice oxygen results in a non-catalytic formation of CO2 by oxidation of CO originating from catalytic dehydrogenation. |
Address |
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Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
Language |
|
Wos |
000275580600002 |
Publication Date |
2010-01-15 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0926-860X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.339 |
Times cited |
20 |
Open Access |
|
Notes |
Esteem 026019 |
Approved |
Most recent IF: 4.339; 2010 IF: 3.384 |
Call Number |
UA @ lucian @ c:irua:81741 |
Serial |
292 |
Permanent link to this record |
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|
|
Author |
Lorenz, H.; Zhao, Q.; Turner, S.; Lebedev, O.I.; Van Tendeloo, G.; Kloetzer, B.; Rameshan, C.; Pfaller, K. |
Title |
Origin of different deactivation of Pd/SnO2 and Pd/GeO2 catalysts in methanol dehydrogenation and reforming: a comparative study |
Type |
A1 Journal article |
Year |
2010 |
Publication |
Applied catalysis : A : general |
Abbreviated Journal |
Appl Catal A-Gen |
Volume |
381 |
Issue |
1/2 |
Pages |
242-252 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Pd particles supported on SnO2 and GeO2 have been structurally investigated by X-ray diffraction, (High-Resolution) transmission and scanning electron microscopy after different reductive treatments to monitor the eventual formation of bimetallic phases and catalytically tested in methanol dehydrogenation/ reforming. For both oxides this included a thin film sample with well-defined Pd particles and a powder catalyst prepared by incipient wetness impregnation. The hexagonal and the tetragonal polymorph were studied for powder GeO2. Pd2Ge formation was observed on all GeO2-supported catalysts, strongly depending on the specific sample used. Reduction of the thin film at 573K resulted in full transformation into the bimetallic state. The partial solubility of hexagonal GeO2 in water and its thermal structural instability yielded Pd2Ge formation at 473 K, at the cost of a structurally inhomogeneous support and Ge metal formation at higher reduction temperatures. Pd on tetragonal GeO2 entered a state of strong metalsupport interaction after reduction at 573673 K, resulting in coalescing Pd2Ge particles on a sintered and re-crystallized support, apparently partially covering the bimetallic particles and decreasing the catalytic activity. Pd2Ge on amorphous thin film and hexagonal GeO2 converted methanol primarily via dehydrogenation to CO and H2. At 573 K, formation of Pd2Sn and also PdSn occurred on the Pd/SnO2 thin film. Pd3Sn2 (and to some extent Pd2Sn) were predominantly obtained on the respective powder catalyst. Strong deactivation with increasing reduction temperature was observed, likely not based on the classical strong metalsupport interaction effect, but rather on a combination of missing active structural ensembles on Sn-enriched bimetallic phases and the formation of metallic -Sn. Correlations to Pd and its bimetallics supported on ZnO, Ga2O3 and In2O3 were also discussed. |
Address |
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Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
Language |
|
Wos |
000279100700029 |
Publication Date |
2010-04-26 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0926-860X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.339 |
Times cited |
14 |
Open Access |
|
Notes |
Esteem 026019 |
Approved |
Most recent IF: 4.339; 2010 IF: 3.384 |
Call Number |
UA @ lucian @ c:irua:83927 |
Serial |
2522 |
Permanent link to this record |
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Author |
Lorenz, H.; Turner, S.; Lebedev, O.I.; Van Tendeloo, G.; Klötzer, B.; Rameshan, C.; Pfaller, K.; Penner, S. |
Title |
Pd-In2O3 interaction due to reduction in hydrogen: consequences for methanol steam reforming |
Type |
A1 Journal article |
Year |
2010 |
Publication |
Applied catalysis : A : general |
Abbreviated Journal |
Appl Catal A-Gen |
Volume |
374 |
Issue |
1/2 |
Pages |
180-188 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Two different Pd/In2O3 samples including a thin film model catalyst with well-defined Pd particles grown on NaCl(0 0 1) supports and a powder catalyst prepared by an impregnation technique are examined by electron microscopy, X-ray diffraction and catalytic measurements in methanol steam reforming in order to correlate the formation of different oxide-supported bimetallic PdIn phases with catalytic activity and selectivity. A PdIn shell around the Pd particles is observed on the thin film catalyst after embedding the Pd particles in In2O3 at 300 K, likely because alloying to PdIn and oxidation to In2O3 are competing processes. Increased PdIn bimetallic formation is observed up to 573 K reduction temperature until at 623 K the film stability limit in hydrogen is reached. Oxidative treatments at 573 K lead to decomposition of PdIn and to the formation of an In2O3 shell covering the Pd particles, which irreversibly changes the activity and selectivity pattern to clean In2O3. PdIn and Pd2In3 phases are obtained on the powder catalyst after reduction at 573 K and 673 K, respectively. Only CO2-selective methanol steam reforming is observed in the reduction temperature range between 473 K and 573 K. After reduction at 673 K encapsulation of the bimetallic particles by crystalline In2O3 suppresses CO2 formation and only activity and selectivity of clean In2O3 are measured. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
Language |
|
Wos |
000274869900023 |
Publication Date |
2009-12-18 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0926-860X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.339 |
Times cited |
55 |
Open Access |
|
Notes |
Esteem 026019 |
Approved |
Most recent IF: 4.339; 2010 IF: 3.384 |
Call Number |
UA @ lucian @ c:irua:81801 |
Serial |
3553 |
Permanent link to this record |
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|
|
Author |
Van Aelst, J.; Philippaerts, A.; Turner, S.; Van Tendeloo, G.; Jacobs, P.; Sels, B. |
Title |
Heterogeneous conjugation of vegetable oil with alkaline treated highly dispersed Ru/USY catalysts |
Type |
A1 Journal article |
Year |
2016 |
Publication |
Applied catalysis : A : general |
Abbreviated Journal |
Appl Catal A-Gen |
Volume |
526 |
Issue |
526 |
Pages |
172-182 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Heterogeneous metal catalysts enable the direct conjugation of linoleic acid tails in vegetable oil to their conjugated linoleic acid (CIA) isomers. CIA-enriched oils are useful as renewable feedstock for the chemical industry and as nutraceutical. Up to now, a solvent-free process for conjugated oils without significant formation of undesired hydrogenation products was not existing. This work shows the design of Ru/USY catalysts able to directly conjugate highly unsaturated vegetable oils such as safflower oil in absence of solvent and hydrogen. Key is fast molecular transport of the bulky reagent and reactive product triglycerides in the zeolite crystal. A two-step zeolite post-synthetic treatment (with NH4OH and acetate salt) was applied to create the necessary mesoporosity. More open zeolite structures allow for a faster conjugation reaction, while securing a fast removal of the reactive conjugated triglycerides, otherwise rapidly deactivating through fouling and pore blockage by polymers. The best Ru/USY catalyst in this contribution is capable of producing exceptionally high yields of conjugated oils, containing up to almost 30 wt% conjugated fatty acid tails in safflower oil, at an initial production rate of 328 g(CLA) mL(-1) h(-1) per gram metal catalyst. (C) 2016 Elsevier B.V. All rights reserved. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
Language |
|
Wos |
000384865600021 |
Publication Date |
2016-09-03 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0926-860x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.339 |
Times cited |
1 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 4.339 |
Call Number |
UA @ lucian @ c:irua:137242 |
Serial |
4383 |
Permanent link to this record |
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|
Author |
Kaminsky, F.V.; Ryabchikov, I.D.; McCammon, C.A.; Longo, M.; Abakumov, A.M.; Turner, S.; Heidari, H. |
Title |
Oxidation potential in the Earth's lower mantle as recorded by ferropericlase inclusions in diamond |
Type |
A1 Journal article |
Year |
2015 |
Publication |
Earth and planetary science letters |
Abbreviated Journal |
Earth Planet Sc Lett |
Volume |
417 |
Issue |
417 |
Pages |
49-56 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Ferropericlase (fPer) inclusions from kimberlitic lower-mantle diamonds recovered in the Juina area, Mato Grosso State, Brazil were analyzed with transmission electron microscopy, electron energy-loss spectroscopy and the flank method. The presence of exsolved non-stoichiometric Fe3+-enriched clusters, varying in size from 1-2 nm to 10-15 nm and comprising similar to 3.64 vol.% of fPer was established. The oxidation conditions necessary for fPer formation within the uppermost lower mantle (P = 25 GPa, T = 1960 K) vary over a wide range: Delta log f(o2) (IW) from 1.58 to 7.76 (Delta = 6.2), reaching the fayalite-magnetite-quartz (FMQ) oxygen buffer position. This agrees with the identification of carbonates and free silica among inclusions within lower-mantle Juina diamonds. On the other hand, at the base of the lower mantle Delta log f(o2) values may lie at and below the iron-wustite (IW) oxygen buffer. Hence, the variations of Delta log f(o2) values within the entire sequence of the lower mantle may reach ten logarithmic units, varying from the IW buffer to the FMQ buffer values. The similarity between lower- and upper-mantle redox conditions supports whole mantle convection, as already suggested on the basis of nitrogen and carbon isotopic compositions in lower- and upper-mantle diamonds. The mechanisms responsible for redox differentiation in the lower mantle may include subduction of oxidized crustal material, mechanical separation of metallic phase(s) and silicate-oxide mineral assemblages enriched in ferric iron, as well as transfer of fused silicate-oxide material presumably also enriched in ferric iron through the mantle. (C) 2015 Elsevier B.V. All rights reserved. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
Language |
|
Wos |
000351799400006 |
Publication Date |
2015-03-05 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0012-821X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.409 |
Times cited |
23 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 4.409; 2015 IF: 4.734 |
Call Number |
c:irua:125451 |
Serial |
2539 |
Permanent link to this record |
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|
Author |
Shenderova, O.; Hens, S.; Vlasov, I.; Turner, S.; Lu, Y.-G.; Van Tendeloo, G.; Schrand, A.; Burikov, S.A.; Dolenko, T.A. |
Title |
Carbon-dot-decorated nanodiamonds |
Type |
A1 Journal article |
Year |
2014 |
Publication |
Particle and particle systems characterization |
Abbreviated Journal |
Part Part Syst Char |
Volume |
31 |
Issue |
5 |
Pages |
580-590 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
The synthesis of a new class of fluorescent carbon nanomaterials, carbon-dot-decorated nanodiamonds (CDD-ND), is reported. These CDD-NDs are produced by specific acid treatment of detonation soot, forming tiny rounded sp2 carbon species (carbon dots), 12 atomic layers thick and 12 nm in size, covalently attached to the surface of the detonation diamond nanoparticles. A combination of nanodiamonds bonded with a graphitic phase as a starting material and the application of graphite intercalated acids for oxidation of the graphitic carbon is necessary for the successful production of CDD-ND. The CDD-ND photoluminescence (PL) is stable, 20 times more intense than the intrinsic PL of well-purified NDs and can be tailored by changing the oxidation process parameters. Carbon-dot-decorated DNDs are shown to be excellent probes for bioimaging applications and inexpensive additives for PL nanocomposites. |
Address |
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Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
Weinheim |
Editor |
|
Language |
|
Wos |
000335518900008 |
Publication Date |
2014-01-13 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0934-0866; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.474 |
Times cited |
30 |
Open Access |
|
Notes |
Fwo; 262348 Esmi; 246791 Countatoms |
Approved |
Most recent IF: 4.474; 2014 IF: 3.081 |
Call Number |
UA @ lucian @ c:irua:117332 |
Serial |
280 |
Permanent link to this record |
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|
Author |
Meledina, M.; Turner, S.; Filippousi, M.; Leus, K.; Lobato, I.; Ramachandran, R.K.; Dendooven, J.; Detavernier, C.; Van Der Voort, P.; Van Tendeloo, G. |
Title |
Direct Imaging of ALD Deposited Pt Nanoclusters inside the Giant Pores of MIL-101 |
Type |
A1 Journal article |
Year |
2016 |
Publication |
Particle and particle systems characterization |
Abbreviated Journal |
Part Part Syst Char |
Volume |
33 |
Issue |
33 |
Pages |
382-387 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
MIL-101 giant-pore metal-organic framework (MOF) materials have been loaded with Pt nanoparticles using atomic layer deposition. The final structure has been investigated by aberration-corrected annular dark-field scanning transmission electron microscopy under strictly controlled low dose conditions. By combining the acquired experimental data with image simulations, the position of the small clusters within the individual pores of a metal-organic framework has been determined. The embedding of the Pt nanoparticles is confirmed by electron tomography, which shows a distinct ordering of the highly uniform Pt nanoparticles. The results show that atomic layer deposition is particularly well-suited for the deposition of individual nanoparticles inside MOF framework pores and that, upon proper regulation of the incident electron dose, annular dark-field scanning transmission electron microscopy is a powerful tool for the characterization of this type of materials at a local scale. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
|
Editor |
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Language |
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Wos |
000379970000006 |
Publication Date |
2016-02-20 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0934-0866 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.474 |
Times cited |
11 |
Open Access |
|
Notes |
S.T. and J.D. gratefully acknowledge the FWO Vlaanderen for a postdoctoral scholarship. The Titan microscope used for this investigation was partially funded by the Hercules foundation of the Flemish government. This work was supported by the Belgian IAP-PAI network. K.L. acknowledges the financial support from the Ghent University BOF postdoctoral Grant 01P06813T and UGent GOA Grant 01G00710. C.D. thanks the FWO Vlaanderen, BOF-UGent (GOA 01G01513), and the Hercules Foundation (AUGE/09/014) for financial support. |
Approved |
Most recent IF: 4.474 |
Call Number |
c:irua:131913 |
Serial |
4028 |
Permanent link to this record |
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Author |
Stambula, S.; Gauquelin, N.; Bugnet, M.; Gorantla, S.; Turner, S.; Sun, S.; Liu, J.; Zhang, G.; Sun, X.; Botton, G.A. |
Title |
Chemical structure of nitrogen-doped graphene with single platinum atoms and atomic clusters as a platform for the PEMFC electrode |
Type |
A1 Journal article |
Year |
2014 |
Publication |
The journal of physical chemistry: C : nanomaterials and interfaces |
Abbreviated Journal |
J Phys Chem C |
Volume |
118 |
Issue |
8 |
Pages |
3890-3900 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
A platform for producing stabilized Pt atoms and clusters through the combination of an N-doped graphene support and atomic layer deposition (ALD) for the Pt catalysts was investigated using transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM). It was determined, using imaging and spectroscopy techniques, that a wide range of N-dopant types entered the graphene lattice through covalent bonds without largely damaging its structure. Additionally and most notably, Pt atoms and atomic clusters formed in the absence of nanoparticles. This work provides a new strategy for experimentally producing stable atomic and subnanometer cluster catalysts, which can greatly assist the proton exchange membrane fuel cell (PEMFC) development by producing the ultimate surface area to volume ratio catalyst. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
Language |
|
Wos |
000332188100004 |
Publication Date |
2014-02-12 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1932-7447;1932-7455; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.536 |
Times cited |
57 |
Open Access |
|
Notes |
Fwo |
Approved |
Most recent IF: 4.536; 2014 IF: 4.772 |
Call Number |
UA @ lucian @ c:irua:115571 |
Serial |
352 |
Permanent link to this record |
|
|
|
Author |
Shenderova, O.A.; Vlasov, I.I.; Turner, S.; Van Tendeloo, G.; Orlinskii, S.B.; Shiryaev, A.A.; Khomich, A.A.; Sulyanov, S.N.; Jelezko, F.; Wrachtrup, J. |
Title |
Nitrogen control in nanodiamond produced by detonation shock-wave-assisted synthesis |
Type |
A1 Journal article |
Year |
2011 |
Publication |
The journal of physical chemistry: C : nanomaterials and interfaces |
Abbreviated Journal |
J Phys Chem C |
Volume |
115 |
Issue |
29 |
Pages |
14014-14024 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Development of efficient production methods of nanodiamond (ND) particles containing substitutional nitrogen and nitrogen-vacancy (NV) complexes remains an important goal in the nanodiamond community. ND synthesized from explosives is generally not among the preferred candidates for imaging applications owing to lack of optically active particles containing NV centers. In this paper, we have systematically studied representative classes of NDs produced by detonation shock wave conversion of different carbon precursor materials, namely, graphite and a graphite/hexogen mixture into ND, as well as ND produced from different combinations of explosives using different cooling methods (wet or dry cooling). We demonstrate that (i) the N content in nanodiamond particles can be controlled through a correct selection of the carbon precursor material (addition of graphite, explosives composition); (ii) particles larger than approximately 20 nm may contain in situ produced optically active NV centers, and (iii) in ND produced from explosives, NV centers are detected only in ND produced by wet synthesis. ND synthesized from a mixture of graphite/explosive contains the largest amount of NV centers formed during synthesis and thus deserves special attention. |
Address |
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Corporate Author |
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Thesis |
|
Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
Language |
|
Wos |
000292892500009 |
Publication Date |
2011-06-08 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1932-7447;1932-7455; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.536 |
Times cited |
54 |
Open Access |
|
Notes |
Esteem 026019; Fwo |
Approved |
Most recent IF: 4.536; 2011 IF: 4.805 |
Call Number |
UA @ lucian @ c:irua:91259 |
Serial |
2342 |
Permanent link to this record |
|
|
|
Author |
Mai, H.H.; Kaydashev, V.E.; Tikhomirov, V.K.; Janssens, E.; Shestakov, M.V.; Meledina, M.; Turner, S.; Van Tendeloo, G.; Moshchalkov, V.V.; Lievens, P. |
Title |
Nonlinear optical properties of Ag nanoclusters and nanoparticles dispersed in a glass host |
Type |
A1 Journal article |
Year |
2014 |
Publication |
The journal of physical chemistry: C : nanomaterials and interfaces |
Abbreviated Journal |
J Phys Chem C |
Volume |
118 |
Issue |
29 |
Pages |
15995-16002 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
The nonlinear absorption of Ag atomic clusters and nanoparticles dispersed in a transparent oxyfluoride glass host has been studied. The as-prepared glass, containing 0.15 atom % Ag, shows an absorption band in the UV/violet attributed to the presence of amorphous Ag atomic nanoclusters with an average size of 1.2 nm. Upon heat treatment the Ag nanoclusters coalesce into larger nanoparticles that show a surface plasmon absorption band in the visible. Open aperture z-scan experiments using 480 nm nanosecond laser pulses demonstrated nonsaturated and saturated nonlinear absorption with large nonlinear absorption indices for the Ag nanoclusters and nanoparticles, respectively. These properties are promising, e.g., for applications in optical limiting and objects contrast enhancement. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
Language |
|
Wos |
000339540700049 |
Publication Date |
2014-07-01 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1932-7447;1932-7455; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.536 |
Times cited |
43 |
Open Access |
|
Notes |
FWO; Methusalem; funding from the European Research Council under the seventh Framework Program (FP7); ERC Grant 246791 COUNTATOMS and the EC project IFOX. |
Approved |
Most recent IF: 4.536; 2014 IF: 4.772 |
Call Number |
UA @ lucian @ c:irua:118626 |
Serial |
2353 |
Permanent link to this record |
|
|
|
Author |
Shenderova, O.; Koscheev, A.; Zaripov, N.; Petrov, I.; Skryabin, Y.; Detkov, P.; Turner, S.; Van Tendeloo, G. |
Title |
Surface chemistry and properties of ozone-purified detonation nanodiamonds |
Type |
A1 Journal article |
Year |
2011 |
Publication |
The journal of physical chemistry: C : nanomaterials and interfaces |
Abbreviated Journal |
J Phys Chem C |
Volume |
115 |
Issue |
20 |
Pages |
9827-9837 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Nanodiamond from ozone purification (NDO) demonstrates very distinctive properties within the class of detonation nanodiamonds, namely very high acidity and high colloidal stability in a broad pH range. To understand the origin of these unusual properties of NDO, the nature of the surface functional groups formed during detonation soot oxidation by ozone needs to be revealed. In this work, thermal desorption mass spectrometry (TDMS) and IR spectroscopy were used for the identification of surface groups and it was concluded that carboxylic anhydride groups prevail on the NDO surface. On the basis of the temperature profiles of the desorbed volatile products and their mass balance, it is hypothesized that decomposition of carboxylic anhydride groups from NDO during heating proceeds by two different mechanisms. Other distinctive features of NDO in comparison with air-treated nanodiamond are also reported. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
Language |
|
Wos |
000290652200001 |
Publication Date |
2011-04-28 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1932-7447;1932-7455; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.536 |
Times cited |
105 |
Open Access |
|
Notes |
Esteem 026019; Fwo |
Approved |
Most recent IF: 4.536; 2011 IF: 4.805 |
Call Number |
UA @ lucian @ c:irua:89556 |
Serial |
3394 |
Permanent link to this record |
|
|
|
Author |
Carraro, G.; Maccato, C.; Gasparotto, A.; Warwick, M.E.A.; Sada, C.; Turner, S.; Bazzo, A.; Andreu, T.; Pliekhova, O.; Korte, D.; Lavrenčič Štangar, U.; Van Tendeloo, G.; Morante, J.R.; Barreca, D. |
Title |
Hematite-based nanocomposites for light-activated applications: Synergistic role of TiO2 and Au introduction |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Solar energy materials and solar cells |
Abbreviated Journal |
Sol Energ Mat Sol C |
Volume |
159 |
Issue |
159 |
Pages |
456-466 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Photo-activated processes have been widely recognized as cost-effective and environmentally friendly routes for both renewable energy generation and purification/cleaning technologies. We report herein on a plasma- assisted approach for the synthesis of Fe 2 O 3 -TiO 2 nanosystems functionalized with Au nanoparticles. Fe 2 O 3 nanostructures were grown by plasma enhanced-chemical vapor deposition, followed by the sequential sputtering of titanium and gold under controlled conditions, and final annealing in air. The target nanosystems were subjected to a thorough multi-technique characterization, in order to elucidate the interrelations between their chemico-physical properties and the processing conditions. Finally, the functional performances were preliminarily investigated in both sunlight-assisted H 2 O splitting and photocatalytic activity tests in view of self- cleaning applications. The obtained results highlight the possibility of tailoring the system behaviour and candidate the present Fe 2 O 3 -TiO 2 -Au nanosystems as possible multi-functional low-cost platforms for light-activated processes. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000388053600053 |
Publication Date |
2016-10-07 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0927-0248 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.784 |
Times cited |
15 |
Open Access |
Not_Open_Access |
Notes |
The research leading to these results has received funding from the FP7 project “SOLAROGENIX” (NMP4-SL-2012-310333), as well as from Padova University ex-60% 2013-2016 projects, grant no. CPDR132937/13 (SOLLEONE) and the post-doc fellowship ACTION. INFINITY project in the framework of the EU Erasmus Mundus Action 2 is also acknowledged to provide a Ph.D. financial support as well as Slovenian Research Agency (program P2-0377). The authors are grateful to Dr. E. Toniato (Department of Chemistry, Padova University, Italy) for synthetic assistance and to Prof. E. Bontempi and Dr. M. Brisotto (Chemistry for Technologies Laboratory, Brescia University, Italy) for XRD analyses. |
Approved |
Most recent IF: 4.784 |
Call Number |
EMAT @ emat @ c:irua:135833 |
Serial |
4284 |
Permanent link to this record |
|
|
|
Author |
Batuk, M.; Turner, S.; Abakumov, A.M.; Batuk, D.; Hadermann, J.; Van Tendeloo, G. |
Title |
Atomic structure of defects in anion-deficient perovskite-based ferrites with a crystallographic shear structure |
Type |
A1 Journal article |
Year |
2014 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
Volume |
53 |
Issue |
4 |
Pages |
2171-2180 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Crystallographic shear (CS) planes provide a new structure-generation mechanism in the anion-deficient perovskites containing lone-pair cations. Pb2Sr2Bi2Fe6O16, a new n = 6 representative of the AnBnO3n2 homologous series of the perovskite-based ferrites with the CS structure, has been synthesized using the solid-state technique. The structure is built of perovskite blocks with a thickness of four FeO6 octahedra spaced by double columns of FeO5 edge-sharing distorted tetragonal pyramids, forming 1/2[110](101)p CS planes (space group Pnma, a = 5.6690(2) Å, b = 3.9108(1) Å, c = 32.643(1) Å). Pb2Sr2Bi2Fe6O16 features a wealth of microstructural phenomena caused by the flexibility of the CS planes due to the variable ratio and length of the constituting fragments with {101}p and {001}p orientation. This leads to the formation of waves, hairpins, Γ-shaped defects, and inclusions of the hitherto unknown layered anion-deficient perovskites Bi2(Sr,Pb)Fe3O8.5 and Bi3(Sr,Pb)Fe4O11.5. Using a combination of diffraction, imaging, and spectroscopic transmission electron microscopy techniques this complex microstructure was fully characterized, including direct determination of positions, chemical composition, and coordination number of individual atomic species. The complex defect structure makes these perovskites particularly similar to the CS structures in ReO3-type oxides. The flexibility of the CS planes appears to be a specific feature of the Sr-based system, related to the geometric match between the SrO perovskite layers and the {100}p segments of the CS planes. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Easton, Pa |
Editor |
|
Language |
|
Wos |
000332144100039 |
Publication Date |
2014-01-30 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0020-1669;1520-510X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.857 |
Times cited |
6 |
Open Access |
|
Notes |
Countatoms; FWO |
Approved |
Most recent IF: 4.857; 2014 IF: 4.762 |
Call Number |
UA @ lucian @ c:irua:113507 |
Serial |
198 |
Permanent link to this record |
|
|
|
Author |
Ramezanipour, F.; Greedan, J.E.; Siewenie, J.; Donaberger, R.L.; Turner, S.; Botton, G.A. |
Title |
A vacancy-disordered, oxygen-deficient perovskite with long-range magnetic ordering : local and average structures and magnetic properties of Sr2Fe1.5Cr0.5O5 |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
Volume |
51 |
Issue |
4 |
Pages |
2638-2644 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The local and average crystal structures and magnetic properties of the oxygen-deficient perovskite Sr2Fe1.5Cr0.5O5+y were studied using powder X-ray and neutron diffraction, neutron-pair distribution function analysis, and electron energy-loss spectroscopy. This material crystallizes in the cubic Pm3̅m space group, with a = 3.94491(14) Å. The oxygen vacancies are distributed randomly throughout the perovskite-type structure, and the average coordination number of the Fe(Cr) sites is 5. Refinement of the neutron diffraction data indicates y 0.05. This is in discordance with an earlier report on a material with the same nominal composition and cell constant. Electron energy-loss Cr L2,3-edge spectroscopy shows that Cr3+ is present, which is also contrary to previous speculation. Neutron-pair distribution function studies show that a brownmillerite-like model involving ordered vacancies and alternating octahedral and tetrahedral coordination at the metal sites, gives a better description of the local structure out to 5 Å. A remarkable phenomenon determined by neutron diffraction in Sr2Fe1.5Cr0.5O5 is the occurrence of a long-range G-type antiferromagnetic ordering with Tc ≈ 565 K because cubic oxygen-deficient perovskites with B-site disorder usually do not undergo transitions to magnetically ordered states. The observation of long-range antiferromagnetic order and the Tc value are in accordance with previous Mössbauer spectroscopic studies. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Easton, Pa |
Editor |
|
Language |
|
Wos |
000300466300079 |
Publication Date |
2012-01-30 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0020-1669;1520-510X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.857 |
Times cited |
12 |
Open Access |
|
Notes |
Fwo |
Approved |
Most recent IF: 4.857; 2012 IF: 4.593 |
Call Number |
UA @ lucian @ c:irua:95039 |
Serial |
3828 |
Permanent link to this record |
|
|
|
Author |
Amin-Ahmadi, B.; Connétable, D.; Fivel, M.; Tanguy, D.; Delmelle, R.; Turner, S.; Malet, L.; Godet, S.; Pardoen, T.; Proost, J.; Schryvers, D.; Idrissi, H. |
Title |
Dislocation/hydrogen interaction mechanisms in hydrided nanocrystalline palladium films |
Type |
A1 Journal article |
Year |
2016 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
Volume |
111 |
Issue |
111 |
Pages |
253-261 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
The nanoscale plasticity mechanisms activated during hydriding cycles in sputtered nanocrystalline Pd films have been investigated ex-situ using advanced transmission electron microscopy techniques. The internal stress developing within the films during hydriding has been monitored in-situ. Results showed that in Pd films hydrided to β-phase, local plasticity was mainly controlled by dislocation activity in spite of the small grain size. Changes of the grain size distribution and the crystallographic texture have not been observed. In contrast, significant microstructural changes were not observed in Pd films hydrided to α-phase. Moreover, the effect of hydrogen loading on the nature and density of dislocations has been investigated using aberration-corrected TEM. Surprisingly, a high density of shear type stacking faults has been observed after dehydriding, indicating a significant effect of hydrogen on the nucleation energy barriers of Shockley partial dislocations. Ab-initio calculations of the effect of hydrogen on the intrinsic stable and unstable stacking fault energies of palladium confirm the experimental observations. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000375812100027 |
Publication Date |
2016-04-06 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1359-6454 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
5.301 |
Times cited |
14 |
Open Access |
|
Notes |
This work was carried out in the framework of the IAP program of the Belgian State Federal Office for Scientific, Technical and Cultural Affairs, under Contract No. P7/21. The support of the FWO research project G012012N “Understanding nanocrystalline mechanical behaviour from structural investigations” for B. Amin-Ahmadi is also gratefully acknowledged. This work was granted access to the HPC resources of CALMIP (CICT Toulouse, France) under the allocations 2014-p0912 and 2014-p0749. |
Approved |
Most recent IF: 5.301 |
Call Number |
c:irua:132678 |
Serial |
4054 |
Permanent link to this record |
|
|
|
Author |
Hoang, D.-Q.; Korneychuk, S.; Sankaran, K.J.; Pobedinskas, P.; Drijkoningen, S.; Turner, S.; Van Bael, M.K.; Verbeeck, J.; Nicley, S.S.; Haenen, K. |
Title |
Direct nucleation of hexagonal boron nitride on diamond : crystalline properties of hBN nanowalls |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
Volume |
127 |
Issue |
|
Pages |
17-24 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Hexagonal boron nitride (hBN) nanowalls were deposited by unbalanced radio frequency sputtering on (100)-oriented silicon, nanocrystalline diamond films, and amorphous silicon nitride (Si3N4) membranes. The hBN nanowall structures were found to grow vertically with respect to the surface of all of the substrates. To provide further insight into the nucleation phase and possible lattice distortion of the deposited films, the structural properties of the different interfaces were characterized by transmission electron microscopy. For Si and Si3N4 substrates, turbostratic and amorphous BN phases form a clear transition zone between the substrate and the actual hBN phase of the bulk nanowalls. However, surprisingly, the presence of these phases was suppressed at the interface with a nanocrystalline diamond film, leading to a direct coupling of hBN with the diamond surface, independent of the vertical orientation of the diamond grain. To explain these observations, a growth mechanism is proposed in which the hydrogen terminated surface of the nanocrystalline diamond film leads to a rapid formation of the hBN phase during the initial stages of growth, contrary to the case of Si and Si3N4 substrates. (C) 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Oxford |
Editor |
|
Language |
|
Wos |
|
Publication Date |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1359-6454 |
ISBN |
|
Additional Links |
UA library record; ; WoS full record; WoS citing articles |
Impact Factor |
5.301 |
Times cited |
|
Open Access |
OpenAccess |
Notes |
|
Approved |
Most recent IF: 5.301 |
Call Number |
UA @ lucian @ c:irua:142398 |
Serial |
4645 |
Permanent link to this record |
|
|
|
Author |
Kalidindi, S.B.; Hyunchul, O.; Hirscher, M.; Esken, D.; Wiktor, C.; Turner, S.; Van Tendeloo, G.; Fischer, R.A. |
Title |
Metal@COFs : covalent organic frameworks as templates for Pd nanoparticles and hydrogen storage properties of Pd@COF-102 hybrid material |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Chemistry: a European journal |
Abbreviated Journal |
Chem-Eur J |
Volume |
18 |
Issue |
35 |
Pages |
10848-10856 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Three-dimensional covalent organic frameworks (COFs) have been demonstrated as a new class of templates for nanoparticles. Photodecomposition of the [Pd(eta 3-C3H5)(eta 5-C5H5)]@COF-102 inclusion compound (synthesized by a gas-phase infiltration method) led to the formation of the Pd@COF-102 hybrid material. Advanced electron microscopy techniques (including high-angle annular dark-field scanning transmission electron microscopy and electron tomography) along with other conventional characterization techniques unambiguously showed that highly monodisperse Pd nanoparticles ((2.4 +/- 0.5) nm) were evenly distributed inside the COF-102 framework. The Pd@COF-102 hybrid material is a rare example of a metal-nanoparticle-loaded porous crystalline material with a very narrow size distribution without any larger agglomerates even at high loadings (30 wt %). Two samples with moderate Pd content (3.5 and 9.5 wt %) were used to study the hydrogen storage properties of the metal-decorated COF surface. The uptakes at room temperature from these samples were higher than those of similar systems such as Pd@metalorganic frameworks (MOFs). The studies show that the H2 capacities were enhanced by a factor of 2-3 through Pd impregnation on COF-102 at room temperature and 20 bar. This remarkable enhancement is not just due to Pd hydride formation and can be mainly ascribed to hydrogenation of residual organic compounds, such as bicyclopentadiene. The significantly higher reversible hydrogen storage capacity that comes from decomposed products of the employed organometallic Pd precursor suggests that this discovery may be relevant to the discussion of the spillover phenomenon in metal/MOFs and related systems. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Weinheim |
Editor |
|
Language |
|
Wos |
000307782800013 |
Publication Date |
2012-08-08 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0947-6539; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
5.317 |
Times cited |
88 |
Open Access |
|
Notes |
Fwo |
Approved |
Most recent IF: 5.317; 2012 IF: 5.831 |
Call Number |
UA @ lucian @ c:irua:100469 |
Serial |
2007 |
Permanent link to this record |
|
|
|
Author |
Roesler, C.; Aijaz, A.; Turner, S.; Filippousi, M.; Shahabi, A.; Xia, W.; Van Tendeloo, G.; Muhler, M.; Fischer, R.A. |
Title |
Hollow Zn/Co Zeolitic Imidazolate Framework (ZIF) and Yolk-Shell Metal@Zn/Co ZIF nanostructures |
Type |
A1 Journal article |
Year |
2016 |
Publication |
Chemistry: a European journal |
Abbreviated Journal |
Chem-Eur J |
Volume |
22 |
Issue |
22 |
Pages |
3304-3311 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Metal-organic frameworks (MOFs) feature a great possibility for a broad spectrum of applications. Hollow MOF structures with tunable porosity and multifunctionality at the nanoscale with beneficial properties are desired as hosts for catalytically active species. Herein, we demonstrate the formation of well-defined hollow Zn/Co-based zeolitic imidazolate frameworks (ZIFs) by use of epitaxial growth of Zn-MOF (ZIF-8) on preformed Co-MOF (ZIF-67) nanocrystals that involve in situ self-sacrifice/excavation of the Co-MOF. Moreover, any type of metal nanoparticles can be accommodated in Zn/Co-ZIF shells to generate yolk-shell metal@ZIF structures. Transmission electron microscopy and tomography studies revealed the inclusion of these nanoparticles within hollow Zn/Co-ZIF with dominance of the Zn-MOF as shell. Our findings lead to a generalization of such hollow systems that are working effectively to other types of ZIFs. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Weinheim |
Editor |
|
Language |
|
Wos |
000371419200001 |
Publication Date |
2016-01-29 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0947-6539 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
5.317 |
Times cited |
43 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 5.317 |
Call Number |
UA @ lucian @ c:irua:132347 |
Serial |
4192 |
Permanent link to this record |
|
|
|
Author |
Roesler, C.; Dissegna, S.; Rechac, V.L.; Kauer, M.; Guo, P.; Turner, S.; Ollegott, K.; Kobayashi, H.; Yamamoto, T.; Peeters, D.; Wang, Y.; Matsumura, S.; Van Tendeloo, G.; Kitagawa, H.; Muhler, M.; Llabres i Xamena, F.X.; Fischer, R.A. |
Title |
Encapsulation of bimetallic metal nanoparticles into robust zirconium-based metal-organic frameworks : evaluation of the catalytic potential for size-selective hydrogenation |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Chemistry: a European journal |
Abbreviated Journal |
Chem-Eur J |
Volume |
23 |
Issue |
15 |
Pages |
3583-3594 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The realization of metal nanoparticles (NPs) with bimetallic character and distinct composition for specific catalytic applications is an intensively studied field. Due to the synergy between metals, most bimetallic particles exhibit unique properties that are hardly provided by the individual monometallic counterparts. However, as small-sized NPs possess high surface energy, agglomeration during catalytic reactions is favored. Sufficient stabilization can be achieved by confinement of NPs in porous support materials. In this sense, metal-organic frameworks (MOFs) in particular have gained a lot of attention during the last years; however, encapsulation of bimetallic species remains challenging. Herein, the exclusive embedding of preformed core-shell PdPt and RuPt NPs into chemically robust Zr-based MOFs is presented. Microstructural characterization manifests partial retention of the core-shell systems after successful encapsulation without harming the crystallinity of the microporous support. The resulting chemically robust NP@UiO-66 materials exhibit enhanced catalytic activity towards the liquid-phase hydrogenation of nitrobenzene, competitive with commercially used Pt on activated carbon, but with superior size-selectivity for sterically varied substrates. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Weinheim |
Editor |
|
Language |
|
Wos |
000397502900010 |
Publication Date |
2016-12-06 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0947-6539 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
5.317 |
Times cited |
13 |
Open Access |
Not_Open_Access |
Notes |
; This work is supported by the Cluster of Excellence RESOLV (EXC 1069) funded by the Deutsche Forschungsgemeinschaft (DFG). ; |
Approved |
Most recent IF: 5.317 |
Call Number |
UA @ lucian @ c:irua:142485 |
Serial |
4653 |
Permanent link to this record |
|
|
|
Author |
Vorobyeva, N.; Rumyantseva, M.; Filatova, D.; Konstantinova, E.; Grishina, D.; Abakumov, A.; Turner, S.; Gaskov, A. |
Title |
Nanocrystalline ZnO(Ga) : paramagnetic centers, surface acidity and gas sensor properties |
Type |
A1 Journal article |
Year |
2013 |
Publication |
Sensors and actuators : B : chemical |
Abbreviated Journal |
Sensor Actuat B-Chem |
Volume |
182 |
Issue |
|
Pages |
555-564 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Nanocrystalline ZnO and ZnO(Ga) samples with different gallium content were prepared by wet-chemical method. Introduction of gallium leads to the increase of amount of weak acid sites such as surface hydroxyl groups. Gas sensing properties toward 0.22 ppm H2S and NO2 were studied at 100450 °C by DC conductance measurements. The optimal temperature for gas sensing experiments was determined. Sensor signal toward H2S decreases with increase of Ga concentration. The dependence of ZnO(Ga) sensor signal to NO2 on the gallium content has non-monotonous character, which correlates with the change of conductivity of the samples in air and concentration of paramagnetic donor states. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Lausanne |
Editor |
|
Language |
|
Wos |
000319488800075 |
Publication Date |
2013-03-27 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0925-4005; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
5.401 |
Times cited |
42 |
Open Access |
|
Notes |
Hercules; FWO |
Approved |
Most recent IF: 5.401; 2013 IF: 3.840 |
Call Number |
UA @ lucian @ c:irua:107346 |
Serial |
2250 |
Permanent link to this record |
|
|
|
Author |
Wang, B.; Idrissi, H.; Galceran, M.; Colla, M.S.; Turner, S.; Hui, S.; Raskin, J.P.; Pardoen, T.; Godet, S.; Schryvers, D. |
Title |
Advanced TEM investigation of the plasticity mechanisms in nanocrystalline freestanding palladium films with nanoscale twins |
Type |
A1 Journal article |
Year |
2012 |
Publication |
International journal of plasticity |
Abbreviated Journal |
Int J Plasticity |
Volume |
37 |
Issue |
|
Pages |
140-156 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Nanocrystalline palladium thin films deposited by electron-beam evaporation and deformed by on-chip tensile testing reveal a surprisingly large strain hardening capacity when considering the small similar to 25 nm grain size. The as-grown films contain several coherent single and multifold twin boundaries. The coherency of the twin boundaries considerably decreases with deformation due to dislocation/twin boundary interactions. These reactions are described based on a detailed analysis of the number and the type of dislocations located at the twin boundaries using high-resolution TEM, including aberration corrected microscopy. Sessile Frank dislocations were observed at the twin/matrix interfaces, explaining the loss of the TB coherency due to the Burgers vector pointing out of the twinning plane. Grain boundary mediated processes were excluded as a mechanism dominating the plastic deformation based on the investigation of the grain size distribution as well as the crystallographic texture using Automated Crystallographic Orientation Indexation TEM. Other factors influencing the plastic deformation such as impurities and the presence of a native passivation oxide layer at the surface of the films were investigated using analytical TEM. The twin boundaries observed in the present work partly explain the high strain hardening capacity by providing both increasing resistance to dislocation motion with deformation and a source for dislocation multiplication. (C) 2012 Elsevier Ltd. All rights reserved. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Oxford |
Editor |
|
Language |
|
Wos |
000307416100009 |
Publication Date |
2012-05-16 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0749-6419; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
5.702 |
Times cited |
44 |
Open Access |
|
Notes |
Iap; Fwo |
Approved |
Most recent IF: 5.702; 2012 IF: 4.356 |
Call Number |
UA @ lucian @ c:irua:101082 |
Serial |
74 |
Permanent link to this record |
|
|
|
Author |
Filez, M.; Redekop, E.A.; Poelman, H.; Galvita, V.V.; Meledina, M.; Turner, S.; Van Tendeloo, G.; Detavernier, C.; Marin, G.B. |
Title |
One-pot synthesis of Pt catalysts based on layered double hydroxides: an application in propane dehydrogenation |
Type |
A1 Journal article |
Year |
2016 |
Publication |
Catalysis science & technology |
Abbreviated Journal |
Catal Sci Technol |
Volume |
6 |
Issue |
6 |
Pages |
1863-1869 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Simple methods for producing noble metal catalysts with well-defined active sites and improved performance are highly desired in the chemical industry. However, the development of such methods still presents a formidable synthetic challenge. Here, we demonstrate a one-pot synthesis route for the controlled production of bimetallic Pt–In catalysts based on the single-step formation of Mg,Al,Pt,In-containing layered double hydroxides (LDHs). Besides their simple synthesis, these Pt–In catalysts exhibit superior propane dehydrogenation activity compared to their multi-step synthesized analogs. The presented material serves as a showcase for the one-pot synthesis of a broader class of LDH-derived mono- and multimetallic Pt catalysts. The compositional flexibility provided by LDH materials can pave the way towards highperforming Pt-based catalysts with tunable physicochemical properties. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000372172800031 |
Publication Date |
2015-10-23 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2044-4753 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
5.773 |
Times cited |
12 |
Open Access |
|
Notes |
This work was supported by the Fund for Scientific Research Flanders (FWO: G.0209.11), the ‘Long Term Structural Methusalem Funding by the Flemish Government’, the IAP 7/05 Interuniversity Attraction Poles Programme – Belgian State – Belgian Science Policy, and the Fund for Scientific Research Flanders (FWO-Vlaanderen) by supplying financing of beam time at the DUBBLE beamline of the ESRF and travel costs and a post-doctoral fellowship for S. T. The authors acknowledge the assistance from the DUBBLE (XAS campaign 26-01-979) and SuperXAS staff (Proposal 20131191). E. A. Redekop acknowledges the Marie Curie International Incoming Fellowship granted by the European Commission (Grant Agreement No. 301703). The authors also express their gratitude to O. Janssens for performing ex situ XRD characterization. |
Approved |
Most recent IF: 5.773 |
Call Number |
c:irua:133167 |
Serial |
4057 |
Permanent link to this record |
|
|
|
Author |
Esquivel, D.; Ouwehand, J.; Meledina, M.; Turner, S.; Tendeloo, G.V.; Romero-Salguero, F.J.; Clercq, J.D.; Voort, P.V.D. |
Title |
Thiol-ethylene bridged PMO: A high capacity regenerable mercury adsorbent via intrapore mercury thiolate crystal formation |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Journal of hazardous materials |
Abbreviated Journal |
J Hazard Mater |
Volume |
339 |
Issue |
339 |
Pages |
368-377 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Highly ordered thiol-ethylene bridged Periodic Mesoporous Organosilicas were synthesized directly from a homemade thiol-functionalized bis-silane precursor. These high surface area materials contain up to 4.3 mmol/g sulfur functions in the walls and can adsorb up to 1183 mg/g mercury ions. Raman spectroscopy reveals the existence of thiol and disulfide moieties. These groups have been evaluated by a combination of Raman spectroscopy, Ellman’s reagent and elemental analysis. The adsorption of mercury ions was evidenced by different techniques, including Raman, XPS and porosimetry, which indicate that thiol groups are highly accessible to mercury. Scanning transmission electron microscopy combined with EDX showed an even homogenous distribution of the sulfur atoms throughout the structure, and have revealed for the first time that a fraction of the adsorbed mercury is forming thiolate nanocrystals in the pores. The adsorbent is highly selective for mercury and can be regenerated and reused multiple times, maintaining its structure and functionalities and showing only a marginal loss of adsorption capacity after several runs. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000407188200040 |
Publication Date |
2017-06-22 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0304-3894 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.065 |
Times cited |
12 |
Open Access |
OpenAccess |
Notes |
D.E. thanks the F.W.O. Flanders (Fund Scientific Research) for a postdoctoral grant (3E10813W). J.O. acknowledges also F.W.O. Flanders, research project G006813N, and the research Board of Ghent University, UGent GOA (Concerted Research Actions) (grant 01G00710) for financial support. F. J. R.-S. acknowledges funding of this research by the Spanish Ministry of Economy and Competitiveness (Project MAT2013-44463-R), Andalusian Regional Government (FQM-346 group), and Feder Funds. The Titan microscope used for this investigation was partially funded by the Hercules foundation of the Flemish government. This work was supported by the Belgian IAP-PAI network. |
Approved |
Most recent IF: 6.065 |
Call Number |
EMAT @ emat @ c:irua:144433 |
Serial |
4624 |
Permanent link to this record |
|
|
|
Author |
Leus, K.; Folens, K.; Nicomel, N.R.; Perez, J.P.H.; Filippousi, M.; Meledina, M.; Dirtu, M.M.; Turner, S.; Van Tendeloo, G.; Garcia, Y.; Du Laing, G.; Van Der Voort, P. |
Title |
Removal of arsenic and mercury species from water by covalent triazine framework encapsulated \gamma-Fe2O3 nanoparticles |
Type |
A1 Journal article |
Year |
2018 |
Publication |
Journal of hazardous materials |
Abbreviated Journal |
J Hazard Mater |
Volume |
353 |
Issue |
353 |
Pages |
312-319 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The covalent triazine framework, CTF-1, served as host material for the in situ synthesis of Fe2O3 nanoparticles. The composite material consisted of 20 +/- 2 m% iron, mainly in gamma-Fe2O3 phase. The resulting gamma-Fe2O3@CTF-1 was examined for the adsorption of As-III, As-V and H-II from synthetic solutions and real surface-, ground- and wastewater. The material shows excellent removal efficiencies, independent from the presence of Ca2+, Mg2+ or natural organic matter and only limited dependency on the presence of phosphate ions. Its adsorption capacity towards arsenite (198.0 mg g(-1)), arsenate (102.3 mg g(-1)) and divalent mercury (165.8 mg g(-1)) belongs amongst the best-known adsorbents, including many other iron-based materials. Regeneration of the adsorbent can be achieved for use over multiple cycles without a decrease in performance by elution at 70 degrees C with 0.1 M NaOH, followed by a stirring step in a 5 m% H2O2 solution for As or 0.1 M thiourea and 0.001 M HCl for Hg. In highly contaminated water (100 mu gL(-1)), the adsorbent polishes the water quality to well below the current WHO limits. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
Language |
|
Wos |
000438002800035 |
Publication Date |
2018-04-16 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0304-3894 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.065 |
Times cited |
22 |
Open Access |
OpenAccess |
Notes |
; Karen Leus acknowledges financial support from Ghent University. Nina Ricci Nicomel and Jeffrey Paulo H. Perez thank the funding of the VLIR-UOS. Marinela M. Dirtu acknowledges F.R.S.-FNRS for a Charge de recherches position. Stuart Turner gratefully acknowledges the FWO Vlaanderen for a post-doctoral scholarship. The Titan microscope used for this investigation was partially funded by the Hercules foundation of the Flemish government. This work was supported by the Belgian IAP-PAI network. ; |
Approved |
Most recent IF: 6.065 |
Call Number |
UA @ lucian @ c:irua:152430 |
Serial |
5124 |
Permanent link to this record |
|
|
|
Author |
Lu, Y.-G.; Turner, S.; Ekimov, E.A.; Verbeeck, J.; Van Tendeloo, G. |
Title |
Boron-rich inclusions and boron distribution in HPHT polycrystalline superconducting diamond |
Type |
A1 Journal article |
Year |
2015 |
Publication |
Carbon |
Abbreviated Journal |
Carbon |
Volume |
86 |
Issue |
86 |
Pages |
156-162 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Polycrystalline boron-doped superconducting diamond, synthesized at high pressure and high temperature (HPHT) via a reaction of a single piece of crystalline boron with monolithic graphite, has been investigated by analytical transmission electron microscopy. The local boron distribution and boron environment have been studied by a combination of (scanning) transmission electron microscopy ((S)TEM) and spatially resolved electron energy-loss spectroscopy (EELS). High resolution TEM imaging and EELS elemental mapping have established, for the first time, the presence of largely crystalline diamond-diamond grain boundaries within the material and have evidenced the presence of substitutional boron dopants within individual diamond grains. Confirmation of the presence of substitutional B dopants has been obtained through comparison of acquired boron K-edge EELS fine structures with known references. This confirmation is important to understand the origin of superconductivity in polycrystalline B-doped diamond. In addition to the substitutional boron doping, boron-rich inclusions and triple-points, both amorphous and crystalline, with chemical compositions close to boron carbide B4C, are evidenced. (C) 2015 Elsevier Ltd. All rights reserved. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Oxford |
Editor |
|
Language |
|
Wos |
000352922700019 |
Publication Date |
2015-01-22 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0008-6223; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.337 |
Times cited |
20 |
Open Access |
|
Notes |
FWO; 246791 COUNTATOMS; 278510 VORTEX; Hercules ECASJO_; |
Approved |
Most recent IF: 6.337; 2015 IF: 6.196 |
Call Number |
c:irua:125994UA @ admin @ c:irua:125994 |
Serial |
250 |
Permanent link to this record |
|
|
|
Author |
Philippaerts, A.; Paulussen, S.; Turner, S.; Lebedev, O.I.; Van Tendeloo, G.; Poelman, H.; Bulut, M.; de Clippel, F.; Smeets, P.; Sels, B.; Jacobs, P. |
Title |
Selectivity in sorption and hydrogenation of methyl oleate and elaidate on MFI zeolites |
Type |
A1 Journal article |
Year |
2010 |
Publication |
Journal of catalysis |
Abbreviated Journal |
J Catal |
Volume |
270 |
Issue |
1 |
Pages |
172-184 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Different zeolites were tested for selective removal of methyl elaidate (trans isomer) from an equimolar mixture with methyl oleate (cis isomer). Sorption experiments of the geometric isomers show that only ZSM-5 samples with reduced Al content in the framework are able to discriminate among the bent cis and the linear trans fatty acid methyl esters. Hydrogenation experiments of equimolar methyl oleate and elaidate mixtures at low temperature (65 °C) and high hydrogen pressure (6.0 MPa), using Pt catalysts, confirm this result. Only with a Pt/NaZSM-5 catalyst outspoken selectivity for the hydrogenation of the trans isomer is obtained. In order to prepare a selective Pt/ZSM-5 catalyst, the influence of Pt addition (impregnation, ion-exchange and competitive ion-exchange) and Pt activation (different calcination and reduction temperatures) on the Pt-distribution and Pt particle size was investigated using SEM, bright-field and HR TEM, EDX, electron tomography, CO-chemisorption, XPS, XRD, and UVvis measurements. The best result in terms of hydrogenation activity and selectivity is obtained with a Pt/ZSM-5 catalyst, which is prepared via competitive ion-exchange, followed by slow calcination up to 350 °C under high O2 flow and a reduction up to 500 °C under H2. This preparation method leads to a Pt/ZSM-5 catalyst with the best Pt distribution and the smallest Pt clusters occluded in the zeolite structure. Finally, the influence of zeolite crystal size, morphology, and elemental composition of ZSM-5 on hydrogenation activity and selectivity was investigated in detail. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
San Diego, Calif. |
Editor |
|
Language |
|
Wos |
000275966100021 |
Publication Date |
2010-01-28 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0021-9517; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.844 |
Times cited |
24 |
Open Access |
|
Notes |
FWO; IAP-IV; Methusalem |
Approved |
Most recent IF: 6.844; 2010 IF: 5.415 |
Call Number |
UA @ lucian @ c:irua:82435 |
Serial |
2970 |
Permanent link to this record |
|
|
|
Author |
Leus, K.; Liu, Y.-Y.; Meledina, M.; Turner, S.; Van Tendeloo, G.; van der Voort, P. |
Title |
A MoVI grafted metal organic framework : synthesis, characterization and catalytic investigations |
Type |
A1 Journal article |
Year |
2014 |
Publication |
Journal of catalysis |
Abbreviated Journal |
J Catal |
Volume |
316 |
Issue |
|
Pages |
201-209 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
We present the post-modification of a gallium based Metal Organic Framework, COMOC-4, with a Mo-complex. The resulting Mo@COMOC-4 was characterized by means of N2 sorption, XRPD, DRIFT, TGA, XRF, XPS and TEM analysis. The results demonstrate that even at high Mo-complex loadings on the framework, no aggregation or any Mo or Mo oxide species are formed. Moreover, the Mo@COMOC-4 was evaluated as a catalyst in the epoxidation of cyclohexene, cyclooctene and cyclododecene employing TBHP in decane as oxidant. The post-modified COMOC-4 exhibits a very high selectivity toward the epoxide (up to 100%). Regenerability and stability tests have been carried out demonstrating that the catalyst can be recycled without leaching of Mo or loss of crystallinity. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
San Diego, Calif. |
Editor |
|
Language |
|
Wos |
000340853800020 |
Publication Date |
2014-06-19 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0021-9517; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.844 |
Times cited |
36 |
Open Access |
|
Notes |
European Research Council under the Seventh Framework Program (FP7); ; ERC Grant No. 246791 – COUNTATOMS; Hercules; FWO |
Approved |
Most recent IF: 6.844; 2014 IF: 6.921 |
Call Number |
UA @ lucian @ c:irua:117416 |
Serial |
3546 |
Permanent link to this record |
|
|
|
Author |
Philippaerts, A.; Goossens, S.; Vermandel, W.; Tromp, M.; Turner, S.; Geboers, J.; Van Tendeloo, G.; Jacobs, P.A.; Sels, B.F. |
Title |
Design of Ru-zeolites for hydrogen-free production of conjugated linoleic acid |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Chemsuschem |
Abbreviated Journal |
Chemsuschem |
Volume |
4 |
Issue |
6 |
Pages |
757-767 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
While conjugated vegetable oils are currently used as additives in the drying agents of oils and paints, they are also attractive molecules for making bio-plastics. Moreover, conjugated oils will soon be accepted as nutritional additives for functional food products. While current manufacture of conjugated vegetable oils or conjugated linoleic acids (CLAs) uses a homogeneous base as isomerisation catalyst, a heterogeneous alternative is not available today. This contribution presents the direct production of CLAs over Ru supported on different zeolites, varying in topology (ZSM-5, BETA, Y), Si/Al ratio and countercation (H+, Na+, Cs+). Ru/Cs-USY, with a Si/Al ratio of 40, was identified as the most active and selective catalyst for isomerisation of methyl linoleate (cis-9,cis-12 (C18:2)) to CLA at 165 °C. Interestingly, no hydrogen pre-treatment of the catalyst or addition of hydrogen donors is required to achieve industrially relevant isomerisation productivities, namely, 0.7 g of CLA per litre of solvent per minute. Moreover, the biologically most active CLA isomers, namely, cis-9,trans-11, trans-10,cis-12 and trans-9,trans-11, were the main products, especially at low catalyst concentrations. Ex situ physicochemical characterisation with CO chemisorption, extended X-ray absorption fine structure measurements, transmission electron microscopy analysis, and temperature-programmed oxidation reveals the presence of highly dispersed RuO2 species in Ru/Cs-USY(40). |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Weinheim |
Editor |
|
Language |
|
Wos |
000292214000009 |
Publication Date |
2011-04-20 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1864-5631; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
7.226 |
Times cited |
24 |
Open Access |
|
Notes |
Fwo |
Approved |
Most recent IF: 7.226; 2011 IF: 6.827 |
Call Number |
UA @ lucian @ c:irua:90352 |
Serial |
660 |
Permanent link to this record |