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Author Verbruggen, S.W.; Dirckx, J.J.J.; Martens, J.A.; Lenaerts, S.
Title Surface photovoltage measurements : a quick assessment of the photocatalytic activity? Type A1 Journal article
Year 2013 Publication Catalysis today Abbreviated Journal Catal Today
Volume (up) 209 Issue Pages 215-220
Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Abstract Surface photovoltage (SPV) measurements can contribute to a better understanding of electronic properties of photocatalysts under illumination. Direct linking of SPV data to the actual photocatalytic activity remains troublesome. This work aims to discuss SPV measurements from a photocatalytic point of view. By means of several application-based scenarios we illustrate that the trend between SPV and photocatalysis strongly depends on parameters such as the crystal structure, surface modifications, morphology and humidity. This makes the interpretation far from straightforward.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000319498800035 Publication Date 2013-01-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0920-5861 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.636 Times cited 8 Open Access
Notes ; ; Approved Most recent IF: 4.636; 2013 IF: 3.309
Call Number UA @ admin @ c:irua:106520 Serial 5995
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Author Kurttepeli, M.; Locus, R.; Verboekend, D.; de Clippel, F.; Breynaert, E.; Martens, J.; Sels, B.; Bals, S.
Title Synthesis of aluminum-containing hierarchical mesoporous materials with columnar mesopore ordering by evaporation induced self assembly Type A1 Journal article
Year 2016 Publication Microporous and mesoporous materials: zeolites, clays, carbons and related materials Abbreviated Journal Micropor Mesopor Mat
Volume (up) 234 Issue 234 Pages 186-195
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract The incorporation of aluminum into the silica columns of hierarchical mesoporous materials (HMMs) was studied. The HMMs were synthesized by a combination of hard and soft templating methods, forming mesoporous SBA-15-type silica columns inside the pores of anodic aluminum oxide membranes via evaporation induced self-assembly (EISA). By adding Al-isopropoxide to the EISA-mixture a full tetrahedral incorporation of Al and thus the creation of acid sites was achieved, which was proved by nuclear magnetic resonance spectroscopy. Electron microscopy showed that the use of Al-isopropoxide as an Al source for the HMMs led to a change in the mesopore ordering of silica material from circular hexagonal (donut-like) to columnar hexagonal and a 37% increase in specific surface (BET surface). These results were confirmed by a combination of nitrogen physisorption and small-angle X-ray scattering experiments and can be attributed to a swelling of the P123 micelles with isopropanol. The columnar mesopore ordering of silica is advantageous towards the pore accessibility and therefore preferential for many possible applications including catalysis and adsorption on the acid tetrahedral Al-sites. (C) 2016 Elsevier Inc. All rights reserved.
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Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000383291400020 Publication Date 2016-07-09
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 5 Open Access OpenAccess
Notes ; The Belgian government (Belgian Science Policy Office, Belspo) is acknowledged for financing the Interuniversity Attraction Poles (IAP-PAI). S. B. acknowledges the financial support from the European Research Council (ERC Starting Grant #335078-COLOURATOMS). D. V. acknowledges the Flanders Research Foundation (FWO). ; ecas_Sara Approved Most recent IF: 3.615
Call Number UA @ lucian @ c:irua:137108 Serial 4404
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Author Verheyen, E.; Jo, C.; Kurttepeli, M.; Vanbutsele, G.; Gobechiya, E.; Korányi, T.I.; Bals, S.; Van Tendeloo, G.; Ryoo, R.; Kirschhock, C.E.A.; Martens, J.A.;
Title Molecular shape-selectivity of MFI zeolite nanosheets in n-decane isomerization and hydrocracking Type A1 Journal article
Year 2013 Publication Journal of catalysis Abbreviated Journal J Catal
Volume (up) 300 Issue Pages 70-80
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract MFI zeolite nanosheets with thickness of 2 and 8 nm were synthesized, transformed into bifunctional catalysts by loading with platinum and tested in n-decane isomerization and hydrocracking. Detailed analysis of skeletal isomers and hydrocracked products revealed that the MFI nanosheets display transition-state shape-selectivity similar to bulk MFI zeolite crystals. The suppressed formation of bulky skeletal isomers and C5 cracking products are observed both in the nanosheets and the bulk crystals grown in three dimensions. This is typical for restricted transition-state shape-selectivity, characteristic for the MFI type pores. It is a first clear example of transition-state shape-selectivity inside a zeolitic nanosheet. Owing to the short diffusion path across the sheets, expression of diffusion-based discrimination of reaction products in the MFI nanosheets was limited. The 2-methylnonane formation among monobranched C10 isomers and 2,7-dimethyloctane among dibranched C10 isomers, which in MFI zeolite are favored by product diffusion, was much less favored on the nanosheets compared to the reference bulk ZSM-5 material.
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Corporate Author Thesis
Publisher Place of Publication San Diego, Calif. Editor
Language Wos 000317558000009 Publication Date 2013-02-07
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 121 Open Access
Notes Methusalem; IAP; Countatoms Approved Most recent IF: 6.844; 2013 IF: 6.073
Call Number UA @ lucian @ c:irua:106186 Serial 2181
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Author Keulemans, M.; Verbruggen, S.W.; Hauchecorne, B.; Martens, J.A.; Lenaerts, S.
Title Activity versus selectivity in photocatalysis : morphological or electronic properties tipping the scale Type A1 Journal article
Year 2016 Publication Journal of catalysis Abbreviated Journal J Catal
Volume (up) 344 Issue Pages 221-228
Keywords A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL)
Abstract In this paper a structure-activity and structure-selectivity relation is established for three commercial TiO2 sources (P25, P90, and PC500). Morphological and electronic parameters of the photocatalysts are determined using widely applicable and inexpensive characterization procedures. More specifically, the electronic properties are rigorously characterized using an electron titration method yielding quantitative information on the amount of defect sites present in the catalyst. Surface photovoltage measurements on the other hand provide complementary information on the charge carrier recombination process. As model reaction, the degradation of a solid layer of stearic acid is studied using an in situ FTIR reaction cell that enables to investigate the catalyst surface and possible formation of reaction intermediates while the reactions are ongoing. We show that the order of photocatalytic conversion is PC500 > P90 > P25, matching the order of favorable morphological properties. In terms of selectivity to CO2 formation (complete mineralization), however, this trend is reversed: P25 > P90 > PC500, now matching the order of advantageous electronic properties, i.e. low charge carrier recombination and high charge carrier generation. With this we intend to provide new mechanistic insights using a wide variety of physical, (wet) chemical and operando analysis methods that aid the development of performant (self-cleaning) photocatalytic materials.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000390182800022 Publication Date 2016-10-15
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 10 Open Access
Notes ; M.K. acknowledges Flemish Agency for Innovation & Entrepreneurship for the doctoral scholarship. S.W.V. acknowledges the Fonds Wetenschappelijk Onderzoek (FWO) for a post-doctoral fellowship. J.A.M. acknowledges the Flemish government for long-term structural funding (Methusalem). ; Approved Most recent IF: 6.844
Call Number UA @ admin @ c:irua:136339 Serial 5926
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