| Records |
| Author |
Schütte, K.; Doddi, A.; Kroll, C.; Meyer, H.; Wiktor, C.; Gemel, C.; Van Tendeloo, G.; Fischer, R.A.; Janiak, C. |
| Title |
Colloidal nickel/gallium nanoalloys obtained from organometallic precursors in conventional organic solvents and in ionic liquids : noble-metal-free alkyne semihydrogenation catalysts |
Type |
A1 Journal article |
Year  |
2014 |
Publication |
Nanoscale |
Abbreviated Journal |
Nanoscale |
| Volume |
6 |
Issue |
10 |
Pages |
5532-5544 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
| Abstract |
Efforts to replace noble-metal catalysts by low-cost alternatives are of constant interest. The organometallic, non-aqueous wet-chemical synthesis of various hitherto unknown nanocrystalline Ni/Ga intermetallic materials and the use of NiGa for the selective semihydrogenation of alkynes to alkenes are reported. Thermal co-hydrogenolysis of the all-hydrocarbon precursors [Ni(COD)(2)] (COD = 1,5-cyclooctadiene) and GaCp* (Cp* = pentamethylcyclopentadienyl) in high-boiling organic solvents mesitylene and n-decane in molar ratios of 1 : 1, 2 : 3 and 3 : 1 yields the nano-crystalline powder materials of the over-all compositions NiGa, Ni2Ga3 and Ni3Ga, respectively. Microwave induced co-pyrolysis of the same precursors without additional hydrogen in the ionic liquid [BMIm][BF4] (BMIm = 1-butyl-3-methyl-imidazolium) selectively yields the intermetallic phases NiGa and Ni3Ga from the respective 1 : 1 and 3 : 1 molar ratios of the precursors. The obtained materials are characterized by transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), IR, powder X-ray diffraction (PXRD) and atomic absorption spectroscopy (AAS). The single-source precursor [Ni(GaCp*)(PMe3)(3)] with a fixed Ni : Ga stoichiometry of 1 : 1 was employed as well. In comparison with the co-hydrogenolytic dual precursor source approach it turned out to be less practical due to inefficient nickel incorporation caused by the parasitic formation of stable [Ni(PMe3)(4)]. The use of ionic liquid [BMIm][BF4] as a non-conventional solvent to control the reaction and stabilize the nanoparticles proved to be particularly advantageous and stable colloids of the nanoalloys NiGa and Ni3Ga were obtained. A phase-selective Ni/Ga colloid synthesis in conventional solvents and in the presence of surfactants such as hexadecylamine (HDA) was not feasible due to the undesired reactivity of HDA with GaCp* leading to inefficient gallium incorporation. Recyclable NiGa nanoparticles selectively semihydrogenate 1-octyne and diphenylacetylene (tolan) to 1-octene and diphenylethylene, respectively, with a yield of about 90% and selectivities of up to 94 and 87%. Ni-NPs yield alkanes with a selectivity of 97 or 78%, respectively, under the same conditions. |
| Address |
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| Corporate Author |
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Thesis |
|
| Publisher |
|
Place of Publication |
Cambridge |
Editor |
|
| Language |
|
Wos |
000335148800069 |
Publication Date |
2014-03-06 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2040-3364;2040-3372; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
7.367 |
Times cited |
40 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 7.367; 2014 IF: 7.394 |
| Call Number |
UA @ lucian @ c:irua:117251 |
Serial |
390 |
| Permanent link to this record |
| |
|
| |
| Author |
Wiktor, C. |
| Title |
Characterization of metal-organic frameworks and other porous materials via advanced transmission electron microscopy |
Type |
Doctoral thesis |
| Year |
2014 |
Publication |
|
Abbreviated Journal |
|
| Volume |
|
Issue |
|
Pages |
|
| Keywords |
Doctoral thesis; Electron microscopy for materials research (EMAT) |
| Abstract |
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| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
Antwerpen |
Editor |
|
| Language |
|
Wos |
|
Publication Date |
0000-00-00 |
| Series Editor |
|
Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
|
Edition |
|
| ISSN |
|
ISBN |
|
Additional Links |
UA library record |
| Impact Factor |
|
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
Most recent IF: NA |
| Call Number |
UA @ lucian @ c:irua:123905 |
Serial |
325 |
| Permanent link to this record |
| |
|
| |
| Author |
Mei, B.; Wiktor, C.; Turner, S.; Pougin, A.; Van Tendeloo, G.; Fischer, R.A.; Muhler, M.; Strunk, J. |
| Title |
Evidence for metalsupport interactions in Au modified TiOx/SBA-15 materials prepared by photodeposition |
Type |
A1 Journal article |
| Year |
2013 |
Publication |
ACS catalysis |
Abbreviated Journal |
Acs Catal |
| Volume |
3 |
Issue |
12 |
Pages |
3041-3049 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Gold nanoparticles have been efficiently photodeposited onto titanate-loaded SBA-15 (Ti(x)/SBA-15) with different titania coordination. Transmission electron microscopy shows that relatively large Au nanoparticles are photodeposited on the outer surface of the Ti(x)/SBA-15 materials and that TiOx tends to form agglomerates in close proximity to the Au nanoparticles, often forming coreshell Au/TiOx structures. This behavior resembles typical processes observed due to strong-metal support interactions. In the presence of gold, the formation of hydrogen on Ti(x)/SBA-15 during the photodeposition process and the performance in the hydroxylation of terephthalic acid is greatly enhanced. The activity of the Au/Ti(x)/SBA-15 materials is found to depend on the TiOx loading, increasing with a larger amount of initially isolated TiO4 tetrahedra. Samples with initially clustered TiOx species show lower photocatalytic activities. When isolated zinc oxide (ZnOx) species are present on Ti(x)/SBA-15, gold nanoparticles are smaller and well dispersed within the pores. Agglomeration of TiOx species and the formation of Au/TiOx structures is negligible. The dispersion of gold and the formation of Au/TiOx in the SBA-15 matrix seem to depend on the mobility of the TiOx species. The mobility is determined by the initial degree of agglomeration of TiOx. Effective hydrogen evolution requires Au/TiOx coreshell composites as in Au/Ti(x)/SBA-15, whereas hydroxylation of terephthalic acid can also be performed with Au/ZnOx/TiOx/SBA-15 materials. However, isolated TiOx species have to be grafted onto the support prior to the zinc oxide species, providing strong evidence for the necessity of TiOSi bridges for high photocatalytic activity in terephthalic acid hydroxylation. |
| 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 |
|
| Language |
|
Wos |
000328231400044 |
Publication Date |
2013-11-05 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2155-5435;2155-5435; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
10.614 |
Times cited |
22 |
Open Access |
|
| Notes |
262348 ESMI; FWO; 246791 COUNTATOMS; IAP-PAI; Hercules |
Approved |
Most recent IF: 10.614; 2013 IF: 7.572 |
| Call Number |
UA @ lucian @ c:irua:112502 |
Serial |
1094 |
| Permanent link to this record |
| |
|
| |
| Author |
Kalidindi, S.B.; Wiktor, C.; Ramakrishnan, A.; Weßing, J.; Schneemann, A.; Van Tendeloo, G.; Fischer, R.A. |
| Title |
Lewis base mediated efficient synthesis and solvation-like host-guest chemistry of covalent organic framework-1 |
Type |
A1 Journal article |
| Year |
2013 |
Publication |
Chemical communications |
Abbreviated Journal |
Chem Commun |
| Volume |
49 |
Issue |
5 |
Pages |
463-465 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
N-Lewis base mediated room temperature synthesis of covalent organic frameworks (COFs) starting from a solution of building blocks instead of partially soluble building blocks was developed. This protocol shifts COF synthetic chemistry from sealed tubes to open beakers. Non-conventional inclusion compounds of COF-1 were obtained by vapor phase infiltration of ferrocene and azobenzene, and solvation like effects were established. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
London |
Editor |
|
| Language |
|
Wos |
000312193100007 |
Publication Date |
2012-11-06 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1359-7345;1364-548X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
6.319 |
Times cited |
17 |
Open Access |
|
| Notes |
262348 Esmi |
Approved |
Most recent IF: 6.319; 2013 IF: 6.718 |
| Call Number |
UA @ lucian @ c:irua:105953 |
Serial |
1815 |
| 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 |
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| Corporate Author |
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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 |
Wiktor, C.; Turner, S.; Zacher, D.; Fischer, R.A.; Van Tendeloo, G. |
| Title |
Imaging of intact MOF-5 nanocrystals by advanced TEM at liquid |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Microporous and mesoporous materials: zeolites, clays, carbons and related materials |
Abbreviated Journal |
Micropor Mesopor Mat |
| Volume |
162 |
Issue |
|
Pages |
131-135 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
| Abstract |
First results on the imaging of intact metalorganic framework (MOF) pores in MOF-5 nanocrystals by aberration corrected transmission electron microscopy (TEM) under liquid nitrogen conditions are presented. The applied technique is certainly transferable to other MOF systems, permitting detailed studies of MOF interfaces, MOFnanoparticle interaction and MOF thin films. |
| Address |
|
| Corporate Author |
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Thesis |
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| Publisher |
|
Place of Publication |
Amsterdam |
Editor |
|
| Language |
|
Wos |
000308284800018 |
Publication Date |
2012-06-18 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1387-1811; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.615 |
Times cited |
30 |
Open Access |
|
| Notes |
Fwo |
Approved |
Most recent IF: 3.615; 2012 IF: 3.365 |
| Call Number |
UA @ lucian @ c:irua:100467 |
Serial |
1554 |
| Permanent link to this record |
| |
|
| |
| Author |
Wee, L.H.; Wiktor, C.; Turner, S.; Vanderlinden, W.; Janssens, N.; Bajpe, S.R.; Houthoofd, K.; Van Tendeloo, G.; De Feyter, S.; Kirschhock, C.E.A.; Martens, J.A.; |
| Title |
Copper benzene tricarboxylate metal-organic framework with wide permanent mesopores stabilized by keggin polyoxometallate ions |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Journal of the American Chemical Society |
Abbreviated Journal |
J Am Chem Soc |
| Volume |
134 |
Issue |
26 |
Pages |
10911-10919 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Porous solids with organized multiple porosity are of scientific and technological importance for broadening the application range from traditional areas of catalysis and adsorption/separation to drug release and biomedical imaging. Synthesis of crystalline porous materials offering a network of uniform micro- and mesopores remains a major scientific challenge. One strategy is based on variation of synthesis parameters of microporous networks, such as, for example, zeolites or metal organic frameworks (MOFs). Here, we show the rational development of an hierarchical variant of the microporous cubic Cu-3(BTC)(2) (BTC = 1,3,5-benzenetricarboxylate) HKUST-1 MOF having strictly repetitive S inn wide mesopores separated by uniform microporous walls in a single crystal structure. This new material coined COK-15 (COK = Centrum voor Oppervlaktechemie en Katalyse) was synthesized via a dual-templating approach. Stability was enhanced by Keggin type phosphotungstate (HPW) systematically occluded in the cavities constituting the walls between the mesopores. |
| Address |
|
| Corporate Author |
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Thesis |
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| Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
| Language |
|
Wos |
000305863900037 |
Publication Date |
2012-06-06 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0002-7863;1520-5126; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
13.858 |
Times cited |
83 |
Open Access |
|
| Notes |
Iap; Fwo |
Approved |
Most recent IF: 13.858; 2012 IF: 10.677 |
| Call Number |
UA @ lucian @ c:irua:100330 |
Serial |
514 |
| Permanent link to this record |
| |
|
| |
| Author |
Nayuk, R.; Zacher, D.; Schweins, R.; Wiktor, C.; Fischer, R.A.; Van Tendeloo, G.; Huber, K. |
| Title |
Modulated formation of MOF-5 nanoparticles : a SANS analysis |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
The journal of physical chemistry: C : nanomaterials and interfaces |
Abbreviated Journal |
J Phys Chem C |
| Volume |
116 |
Issue |
10 |
Pages |
6127-6135 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
| Abstract |
MOF-5 nanoparticles were prepared by mixing a solution of [Zn4O(C6H5COO)(6)] with a solution of benzene-1,4-dicarboxylic acid in DMF at ambient conditions. The former species mimics as a secondary building unit (SBU), and the latter acts as linker. Mixing of the two solutions induced the formation of MOF-5 nanoparticles in dilute suspension. The applied conditions were identified as suitable for a closer investigation of the particle formation process by combined light and small angle neutron scattering (SANS). Scattering analysis revealed a significant impact of the molar ratio of the two components in the reaction mixture. Excessive use of the building unit slowed down the process. A similar effect was observed upon addition of 4n-decylbenzoic acid, which is supposed to act as a modulator. The formation mechanism leads to initial intermediates, which turn into cubelike nanoparticles with a diameter of about 60-80 nm. This initial stage is followed by an extended formation period, where nucleation proceeds over hours, leading to an increasing number of nanoparticles with the same final size of 60-80 nm. |
| Address |
|
| Corporate Author |
|
Thesis |
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| Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
| Language |
|
Wos |
000301509600020 |
Publication Date |
2012-02-16 |
| 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 |
24 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 4.536; 2012 IF: 4.814 |
| Call Number |
UA @ lucian @ c:irua:97789 |
Serial |
2163 |
| Permanent link to this record |
| |
|
| |
| Author |
Esken, D.; Turner, S.; Wiktor, C.; Kalidindi, S.B.; Van Tendeloo, G.; Fischer, R.A. |
| Title |
GaN@ZIF-8 : selective formation of gallium nitride quantum dots inside a zinc methylimidazolate framework |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Journal of the American Chemical Society |
Abbreviated Journal |
J Am Chem Soc |
| Volume |
133 |
Issue |
41 |
Pages |
16370-16373 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
The microporous zeolitic imidazolate framework [Zn(MeIM)2; ZIF-8; MeIM = imidazolate-2-methyl] was quantitatively loaded with trimethylamine gallane [(CH3)3NGaH3]. The obtained inclusion compound [(CH3)3NGaH3]@ZIF-8 reveals three precursor molecules per host cavity. Treatment with ammonia selectively yields the caged cyclotrigallazane intermediate (H2GaNH2)3@ZIF-8, and further annealing gives GaN@ZIF-8. This new composite material was characterized with FT-IR spectroscopy, solid-state NMR spectroscopy, powder X-ray diffraction, elemental analysis, (scanning) transmission electron microscopy combined with electron energy-loss spectroscopy, photoluminescence (PL) spectroscopy, and N2 sorption measurements. The data give evidence for the presence of GaN nanoparticles (13 nm) embedded in the cavities of ZIF-8, including a blue-shift of the PL emission band caused by the quantum size effect. |
| Address |
|
| Corporate Author |
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Thesis |
|
| Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
| Language |
|
Wos |
000295997500014 |
Publication Date |
2011-09-13 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0002-7863;1520-5126; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
13.858 |
Times cited |
82 |
Open Access |
|
| Notes |
Hercules |
Approved |
Most recent IF: 13.858; 2011 IF: 9.907 |
| Call Number |
UA @ lucian @ c:irua:93582 |
Serial |
1315 |
| Permanent link to this record |
| |
|
| |
| Author |
Esken, D.; Noei, H.; Wang, Y.; Wiktor, C.; Turner, S.; Van Tendeloo, G.; Fischer, R.A. |
| Title |
ZnO@ZIF-8 : stabilization of quantum confined ZnO nanoparticles by a zinc methylimidazolate framework and their surface structural characterization probed by CO2 adsorption |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Journal of materials chemistry |
Abbreviated Journal |
J Mater Chem |
| Volume |
21 |
Issue |
16 |
Pages |
5907-5915 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
The microporous and activated zeolitic imidazolate framework (Zn(MeIM)2; MeIM = imidazolate-2-methyl; ZIF-8) was loaded with the MOCVD precursor diethyl zinc [Zn(C2H5)2]. Exposure of ZIF-8 to the vapour of the volatile organometallic molecule resulted in the formation of the inclusion compound [Zn(C2H5)2]0.38@ZIF-8 revealing two precursor molecules per cavity. In a second step the obtained material was treated with oxygen (5 vol% in argon) at various temperatures (oxidative annealing) to achieve the composite material ZnO0.35@ZIF-8. The new material was characterized with powder XRD, FT-IR, UV-vis, solid state NMR, elemental analysis, N2 sorption measurements, and transmission electron microscopy. The data give evidence for the presence of nano-sized ZnO particles stabilized by ZIF-8 showing a blue-shift of the UV-vis absorption caused by quantum size effect (QSE). The surface structure and reactivity of embedded ZnO nanoparticles were characterized via carbon dioxide adsorption at different temperatures monitored by ultra-high vacuum FTIR techniques. It was found that the surface of ZnO nanoparticles is dominated by polar OZnO and ZnZnO facets as well as by defect sites, which all exhibit high reactivity towards CO2 activation forming various adsorbed carbonate and chemisorbed CO2δ− species. |
| Address |
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| Corporate Author |
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Thesis |
|
| Publisher |
|
Place of Publication |
Cambridge |
Editor |
|
| Language |
|
Wos |
000289260000012 |
Publication Date |
2011-03-19 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0959-9428;1364-5501; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
|
Times cited |
76 |
Open Access |
|
| Notes |
Esteem 026019 |
Approved |
Most recent IF: NA |
| Call Number |
UA @ lucian @ c:irua:88641 |
Serial |
3936 |
| Permanent link to this record |
