| Records |
| Author |
Ennaert, T.; Geboers, J.; Gobechiya, E.; Courtin, C.M.; Kurttepeli, M.; Houthoofd, K.; Kirschhock, C.E.A.; Magusin, P.C.M.M.; Bals, S.; Jacobs, P.A.; Sels, B.F. |
| Title |
Conceptual frame rationalizing the self-stabilization of H-USY zeolites in hot liquid water |
Type |
A1 Journal article |
| Year |
2015 |
Publication |
ACS catalysis |
Abbreviated Journal |
Acs Catal |
| Volume |
5 |
Issue |
5 |
Pages |
754-768 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
The wide range of liquid-phase reactions required for the catalytic conversion of biomass compounds into new bioplatform molecules defines a new set of challenges for the development of active, selective, and stable catalysts. The potential of bifunctional Ru/H-USY catalysts for conversions in hot liquid water (HLW) is assessed in terms of physicochemical stability and long-term catalytic performance of acid sites and noble metal functionality, as probed by hydrolytic hydrogenation of cellulose. It is shown that zeolite desilication is the main zeolite degradation mechanism in HLW. USY zeolite stability depends on two main parameters, viz., framework and extra-framework aluminum content. The former protects the zeolite lattice by counteracting hydrolysis of framework bonds, and the latter, when located at the external crystal surface, prevents solubilization of the zeolite framework which is the result of its low water-solubility. Hence, the hot liquid water stability of commercial H-USY zeolites, in contrast to their steam stability, increased with decreasing Si/AI ratio. As a result, mildly steamed USY zeolites containing a high amount of both Al species exhibit the highest resistance to HLW. During an initial period of transformations, Al-rich zeolites form additional protective extra-framework Al species at the outer surface, self-stabilizing the framework. A critical bulk Si/AI ratio of 3 was determined whereby USY zeolites with a lower Si/AI ratio will self-stabilize over time. Besides, due to the initial transformation period, the accessibility of the catalytic active sites is extensively enhanced resulting in a material that is more stable and drastically more accessible to large substrates than the original zeolite. When these findings are applied in the hydrolytic hydrogenation of cellulose, unprecedented nearly quantitative hexitol yields were obtained with a stable catalytic system. |
| Address |
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| Corporate Author |
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Thesis |
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Publisher  |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000349275300031 |
Publication Date |
2014-12-09 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2155-5435;2155-5435; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
10.614 |
Times cited |
65 |
Open Access |
OpenAccess |
| Notes |
335078 Colouratom; ECAS_Sara; (ROMEO:white; preprint:; postprint:restricted 12 months embargo; pdfversion:cannot); |
Approved |
Most recent IF: 10.614; 2015 IF: 9.312 |
| Call Number |
c:irua:125288 |
Serial |
474 |
| Permanent link to this record |
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| Author |
Lueangchaichaweng, W.; Brooks, N.R.; Fiorilli, S.; Gobechiya, E.; Lin, K.; Li, L.; Parres-Esclapez, S.; Javon, E.; Bals, S.; Van Tendeloo, G.; Martens, J.A.; Kirschhock, C.E.A.; Jacobs, P.A.; Pescarmona, P.P.; |
| Title |
Gallium oxide nanorods : novel, template-free synthesis and high catalytic activity in epoxidation reactions |
Type |
A1 Journal article |
| Year |
2014 |
Publication |
Angewandte Chemie: international edition in English |
Abbreviated Journal |
Angew Chem Int Edit |
| Volume |
53 |
Issue |
6 |
Pages |
1585-1589 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Gallium oxide nanorods with unprecedented small dimensions (20-80nm length and 3-5nm width) were prepared using a novel, template-free synthesis method. This nanomaterial is an excellent heterogeneous catalyst for the sustainable epoxidation of alkenes with H2O2, rivaling the industrial benchmark microporous titanosilicate TS-1 with linear alkenes and being much superior with bulkier substrates. A thorough characterization study elucidated the correlation between the physicochemical properties of the gallium oxide nanorods and their catalytic performance, and underlined the importance of the nanorod morphology for generating a material with high specific surface area and a high number of accessible acid sites. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
Weinheim |
Editor |
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| Language |
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Wos |
000330558400021 |
Publication Date |
2014-01-22 |
| 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 |
1433-7851; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
11.994 |
Times cited |
61 |
Open Access |
OpenAccess |
| Notes |
START 1; Methusalem; Prodex; IAP-PAI; and the ERC (grant number 24691-COUNTATOMS and grant number 335078-COLOURATOM) projects; ECAS_Sara; (ROMEO:yellow; preprint:; postprint:restricted ; pdfversion:cannot); |
Approved |
Most recent IF: 11.994; 2014 IF: 11.261 |
| Call Number |
UA @ lucian @ c:irua:115726 |
Serial |
1314 |
| Permanent link to this record |
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| Author |
Van Aelst, J.; Verboekend, D.; Philippaerts, A.; Nuttens, N.; Kurttepeli, M.; Gobechiya, E.; Haouas, M.; Sree, S.P.; Denayer, J.F.M.; Martens, J.A.; Kirschhock, C.E.A.; Taulelle, F.; Bals, S.; Baron, G.V.; Jacobs, P.A.; Sels, B.F. |
| Title |
Catalyst design by NH4OH treatment of USY zeolite |
Type |
A1 Journal article |
| Year |
2015 |
Publication |
Advanced functional materials |
Abbreviated Journal |
Adv Funct Mater |
| Volume |
25 |
Issue |
25 |
Pages |
7130-7144 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
| Abstract |
Hierarchical zeolites are a class of superior catalysts which couples the intrinsic zeolitic properties to enhanced accessibility and intracrystalline mass transport to and from the active sites. The design of hierarchical USY (Ultra-Stable Y) catalysts is achieved using a sustainable postsynthetic room temperature treatment with mildly alkaline NH4OH ( 0.02(M)) solutions. Starting from a commercial dealuminated USY zeolite (Si/Al = 47), a hierarchical material is obtained by selective and tuneable creation of interconnected and accessible small mesopores (2- 6 nm). In addition, the treatment immediately yields the NH4+ form without the need for additional ion exchange. After NH4OH modification, the crystal morphology is retained, whereas the microporosity and relative crystallinity are decreased. The gradual formation of dense amorphous phases throughout the crystal without significant framework atom leaching rationalizes the very high material yields (>90%). The superior catalytic performance of the developed hierarchical zeolites is demonstrated in the acid-catalyzed isomerization of alpha-pinene and the metal-catalyzed conjugation of safflower oil. Significant improvements in activity and selectivity are attained, as well as a lowered susceptibility to deactivation. The catalytic performance is intimately related to the introduced mesopores, hence enhanced mass transport capacity, and the retained intrinsic zeolitic properties. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
Weinheim |
Editor |
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| Language |
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Wos |
000366503700003 |
Publication Date |
2015-10-30 |
| 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 |
1616-301x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
12.124 |
Times cited |
64 |
Open Access |
OpenAccess |
| Notes |
; The authors thank Dr. M. Thommes and Dr. K. Cychosz for numerous and helpful discussions on the correct evaluation of the Ar isotherms. I. Cuppens is acknowledged for ICP-AES analyses. Research was funded through a PhD grant to J.V.A. of the Agency for Innovation by Science and Technology in Flanders (IWT). D.V. and A.P. acknowledge F.W.O.-Vlaanderen (Research Foundation Flanders) for a postdoctoral fellowship. N.N. thanks the KU Leuven for financial support (FLOF). E.G., C.K., and J.M. acknowledge the long-term structural funding by the Flemish Government (Methusalem). S.B. acknowledges the European Research Council for funding under the European Union's Seventh Framework Programme (FP7/2007-2013)/ERC grant agreement No. 335078-COLOURATOMS. The authors are grateful for financial support by the Belgian government through Interuniversity Attraction Poles (IAP-PAI). They also thank Oleon NV for supplying safflower oil. ; ecas_Sara |
Approved |
Most recent IF: 12.124; 2015 IF: 11.805 |
| Call Number |
UA @ lucian @ c:irua:130214 |
Serial |
4147 |
| Permanent link to this record |
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| Author |
Van Aelst, J.; Philippaerts, A.; Bartholomeeusen, E.; Fayad, E.; Thibault-Starzyk, F.; Lu, J.; Schryvers, D.; Ooms, R.; Verboekend, D.; Jacobs, P.; Sels, B. |
| Title |
Towards biolubricant compatible vegetable oils by pore mouth hydrogenation with shape-selective Pt/ZSM-5 catalysts |
Type |
A1 Journal article |
| Year |
2016 |
Publication |
Catalysis science & technology |
Abbreviated Journal |
Catal Sci Technol |
| Volume |
6 |
Issue |
6 |
Pages |
2820-2828 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Pt/ZSM-5 catalysts with various crystal sizes were prepared via competitive ion-exchange, followed by a slow activation procedure. Even when using very large ZSM-5 crystals, highly dispersed Pt nano-clusters were contained within the zeolite crystal's voids, as ascertained by 2D pressure-jump IR spectroscopy of adsorbed CO and focussed ion-beam transmission electron microscopy. The shape-selective properties of the Pt/ZSM-5 catalysts were evaluated in the partial hydrogenation of soybean oil. Unique hydrogenation selectivities were observed, as the fatty acids located at the central position of the triacylglycerol (TAG) molecules were preferentially hydrogenated. The resulting oil has therefore high levels of intermediately melting TAGs, which are compatible with biolubricants due to their improved oxidative stability and still appropriate low-temperature fluidity. The TAG distribution in the partially hydrogenated soybean oil samples was independent from the zeolite crystal size, while the hydrogenation activity linearly increases with the crystal's external surface area. This trend was confirmed with a Pt loaded mesoporous ZSM-5 zeolite, obtained via a mild alkaline treatment. These observations imply and confirm a genuine pore mouth catalysis mechanism, in which only one fatty acid chain of the TAG is able to enter the micropores of ZSM-5, where the double bonds are hydrogenated by the crystal encapsulated Pt-clusters. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000374790200031 |
Publication Date |
2016-03-31 |
| 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 |
2044-4753 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
5.773 |
Times cited |
5 |
Open Access |
|
| Notes |
The research was funded through a PhD grant to J. V. A. of the Agency for Innovation by Science and Technology in Flanders (IWT). A. P. and D. V. acknowledge the F. W. O.-Vlaanderen (Research Foundation Flanders) for a post-doctoral fellowship. E. B. was kindly funded by an F. W. O.-Vlaanderen project. This work was performed in the framework of an Associated International Laboratory between FWO and CNRS. |
Approved |
Most recent IF: 5.773 |
| Call Number |
EMAT @ emat @ c:irua:138981 |
Serial |
4335 |
| Permanent link to this record |
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| Author |
Martens, J.A.; Bogaerts, A.; De Kimpe, N.; Jacobs, P.A.; Marin, G.B.; Rabaey, K.; Saeys, M.; Verhelst, S. |
| Title |
The Chemical Route to a Carbon Dioxide Neutral World |
Type |
A1 Journal article |
| Year |
2017 |
Publication |
Chemsuschem |
Abbreviated Journal |
Chemsuschem |
| Volume |
10 |
Issue |
10 |
Pages |
1039-1055 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
| Abstract |
Excessive CO2 emissions in the atmosphere from anthropogenic activity can be divided into point sources and diffuse sources. The capture of CO2 from flue gases of large industrial installations and its conversion into fuels and chemicals with fast catalytic processes seems technically possible. Some emerging technologies are already being demonstrated on an industrial scale. Others are still being tested on a laboratory or pilot scale. These emerging chemical technologies can be implemented in a time window ranging from 5 to 20 years. The massive amounts of energy needed for capturing processes and the conversion of CO2 should come from low-carbon energy sources, such as tidal, geothermal, and nuclear energy, but also, mainly, from the sun. Synthetic methane gas that can be formed from CO2 and hydrogen gas is an attractive renewable energy carrier with an existing distribution system. Methanol offers advantages as a liquid fuel and is also a building block for the chemical industry. CO2 emissions from diffuse sources is a difficult problem to solve, particularly for CO2 emissions from road, water, and air transport, but steady progress in the development of technology for capturing CO2 from air is being made. It is impossible to ban carbon from the entire energy
supply of mankind with the current technological knowledge, but a transition to a mixed carbon–hydrogen economy can reduce net CO2 emissions and ultimately lead to a CO2-neutral world. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000398182800002 |
Publication Date |
2017-02-24 |
| 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 |
1864-5631 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
7.226 |
Times cited |
75 |
Open Access |
OpenAccess |
| Notes |
This paper is written by members of the Royal Flemish Academy of Belgium for Science and the Arts (KVAB) and external experts. KVAB is acknowledged for supporting the writing and publishing of this viewpoint. Valuable suggestions made by colleagues Jan Kretzschmar, Stan Ulens, and Luc Sterckx are highly appreciated. Special thanks go to Mr. Bert Seghers and Mrs. N. Boelens of KVAB for practical assistance. Mr. Tim Lacoere is acknowledged for graphic design and layout of the figures, and Steven Heylen and Elke Verheyen are acknowledged for data collection and editorial assistance. |
Approved |
Most recent IF: 7.226 |
| Call Number |
PLASMANT @ plasmant @ c:irua:141916 |
Serial |
4532 |
| Permanent link to this record |
