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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. |
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Title |
Selectivity in sorption and hydrogenation of methyl oleate and elaidate on MFI zeolites |
Type |
A1 Journal article |
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Year |
2010 |
Publication |
Journal of catalysis |
Abbreviated Journal  |
J Catal |
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Volume |
270 |
Issue |
1 |
Pages |
172-184 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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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. |
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Place of Publication |
San Diego, Calif. |
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Language |
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Wos |
000275966100021 |
Publication Date |
2010-01-28 |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0021-9517; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.844 |
Times cited |
24 |
Open Access |
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Notes |
FWO; IAP-IV; Methusalem |
Approved |
Most recent IF: 6.844; 2010 IF: 5.415 |
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Call Number |
UA @ lucian @ c:irua:82435 |
Serial |
2970 |
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Author |
Lin, K.; Pescarmona, P.P.; Vandepitte, H.; Liang, D.; Van Tendeloo, G.; Jacobs, P.A. |
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Title |
Synthesis and catalytic activity of Ti-MCM-41 nanoparticles with highly active titanium sites |
Type |
A1 Journal article |
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Year |
2008 |
Publication |
Journal of catalysis |
Abbreviated Journal |
J Catal |
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Volume |
254 |
Issue |
1 |
Pages |
64-70 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Ti-MCM-41 nanoparticles 80-160 nm in diameter (Ti-MCM-41 NP) were successfully prepared by a dilute solution route in sodium hydroxide medium at ambient temperature. Ti-MCM-41 NP were characterized by X-ray diffraction, nitrogen adsorption/desorption isotherms, SEM, TEM. FT-IR, and UV-vis spectroscopy. The characterization results showed the existence of highly ordered hexagonal mesoporous structure and tetrahedral Ti species in Ti-MCM-41 NP. In the epoxidation of cyclohexene with aqueous H2O2, Ti-MCM-41 NP displayed higher conversion and initial reaction rate than a Ti-MCM-41 sample with normal particle size (Ti-MCM-41 LP). Diffusion of the reactants was accelerated and the accessibility to the catalytic Ti species was enhanced in the shorter channels in Ti-MCM-41 NP samples. Ti-MCM-41 NP showed much higher selectivity for cyclohexene oxide compared with Ti-MCM-41 LP, suggesting reduced hydrolysis of cyclohexene oxide with water in the former case. The increased selectivity for cyclohexene oxide can be attributed to the lower concentration of residual surface silanols in Ti-MCM-41 NP and the shorter residence time of epoxide in the shorter mesoporous channels. Ti-MCM-41 NP also appears to be a suitable catalyst in the epoxidation of a bulky substrate, like cholesterol, with tert-butyl hydroperoxide. (c) 2007 Elsevier Inc. All rights reserved. |
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Place of Publication |
San Diego, Calif. |
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Wos |
000253646100006 |
Publication Date |
2008-01-30 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0021-9517; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.844 |
Times cited |
52 |
Open Access |
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Notes |
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Approved |
Most recent IF: 6.844; 2008 IF: 5.167 |
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Call Number |
UA @ lucian @ c:irua:103092 |
Serial |
3409 |
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Author |
de Clippel, F.; Harkiolakis, A.; Vosch, T.; Ke, X.; Giebeler, L.; Oswald, S.; Houthoofd, K.; Jammaer, J.; Van Tendeloo, G.; Martens, J.A.; Jacobs, P.A.; Baron, G.V.; Sels, B.F.; Denayer, J.F.M. |
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Title |
Graphitic nanocrystals inside the pores of mesoporous silica : synthesis, characterization and an adsorption study |
Type |
A1 Journal article |
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Year |
2011 |
Publication |
Microporous and mesoporous materials: zeolites, clays, carbons and related materials |
Abbreviated Journal |
Micropor Mesopor Mat |
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Volume |
144 |
Issue |
1/3 |
Pages |
120-133 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
This work presents a new carbonsilica hybrid material, denoted as CSM, with remarkable sorption properties. It consists of intraporous graphitic nanocrystals grown in the pores of mesoporous silica. CSM is obtained by a subtle incipient wetness impregnation of Al-containing mesoporous silica with furfuryl alcohol (FA)/hemelitol solutions. Both the volume match of the impregnation solution with that of the silica template pore volume, and the presence of Al3+ in the silica, are crucial to polymerize FA selectively inside the mesopores. Carbonization of the intraporous polymer was then performed by pyrolysis under He up to 1273 K. The resulting CSMs were examined by SEM, HRTEM, 27Al MAS NMR, N2 adsorption, XRD, TGA, TPD, XPS, pycnometry and Raman spectroscopy. Mildly oxidized graphitic-like carbon nanoblocks, consisting of a few graphene-like sheets, were thus identified inside the template mesopores. Random stacking of these carbon crystallites generates microporosity resulting in biporous materials at low carbon content and microporous materials at high carbon loadings. Very narrow pore distributions were obtained when pyrolysis was carried out under slow heating rate, viz. 1 K min−1. Adsorption and shape selective properties of the carbon filled mesoporous silica were studied by performing pulse chromatography and breakthrough experiments, and by measuring adsorption isotherms of linear and branched alkanes. Whereas the parent mesoporous silica shows unselective adsorption, their CSM analogues preferentially adsorb linear alkanes. The sorption capacity and selectivity can be adjusted by changing the pore size of the template or by varying the synthesis conditions. A relation between the carbon crystallites size and the shape selective behaviour of the corresponding CSM for instance is demonstrated. Most interestingly, CSM shows separation factors for linear and branched alkanes up to values comparable to those of zeolitic molecular sieves. |
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Place of Publication |
Amsterdam |
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Wos |
000293435400016 |
Publication Date |
2011-04-15 |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1387-1811; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.615 |
Times cited |
15 |
Open Access |
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Notes |
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Approved |
Most recent IF: 3.615; 2011 IF: 3.285 |
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Call Number |
UA @ lucian @ c:irua:92325 |
Serial |
1380 |
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Author |
Hermans, I.; Breynaert, E.; Poelman, H.; de Gryse, R.; Liang, D.; Van Tendeloo, G.; Maes, A.; Peeters, J.; Jacobs, P. |
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Title |
Silica-supported chromium oxide: colloids as building blocks |
Type |
A1 Journal article |
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Year |
2007 |
Publication |
Physical chemistry, chemical physics |
Abbreviated Journal |
Phys Chem Chem Phys |
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Volume |
9 |
Issue |
39 |
Pages |
5382-5386 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
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Place of Publication |
Cambridge |
Editor |
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Wos |
000249925500022 |
Publication Date |
2007-10-03 |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1463-9076;1463-9084; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.123 |
Times cited |
8 |
Open Access |
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Notes |
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Approved |
Most recent IF: 4.123; 2007 IF: 3.343 |
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Call Number |
UA @ lucian @ c:irua:66752 |
Serial |
3000 |
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Author |
Kremer, S.P.B.; Kirschhock, C.E.A.; Aerts, A.; Aerts, C.A.; Houthoofd, K.J.; Grobet, P.J.; Jacobs, P.A.; Lebedev, O.I.; Van Tendeloo, G.; Martens, J.A. |
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Title |
Zeotile-2: a microporous analogue of MCM-48 |
Type |
A1 Journal article |
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Year |
2005 |
Publication |
Solid state sciences |
Abbreviated Journal |
Solid State Sci |
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Volume |
7 |
Issue |
7 |
Pages |
861-867 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
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Corporate Author |
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Publisher |
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Place of Publication |
Amsterdam |
Editor |
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Language |
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Wos |
000230259500006 |
Publication Date |
2005-04-20 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1293-2558; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
1.811 |
Times cited |
10 |
Open Access |
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Notes |
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Approved |
Most recent IF: 1.811; 2005 IF: 1.708 |
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Call Number |
UA @ lucian @ c:irua:54702 |
Serial |
3931 |
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