| Title: | XAS analysis of bifunctional Ni/ZSM-5 catalysts |
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| Authors: | ID Arčon, Iztok (Author)
ID Vu, Hue-Tong (Author)
ID Dražić, Goran (Author)
ID Volavšek, Janez (Author)
ID Mali, Gregor (Author)
ID Zabukovec Logar, Nataša (Author)
ID Novak Tušar, Nataša (Author) |
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| Files: |  https://exrs2024.demokritos.gr/programme/
Description: dostopno z geslom
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| Language: | English |
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| Work type: | Unknown |
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| Typology: | 1.12 - Published Scientific Conference Contribution Abstract |
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| Organization: | UNG - University of Nova Gorica
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| Abstract: | In a bifunctional Ni/ZSM-5 zeolite type catalyst, catalytic properties are usually tuned via varying Al
and Ni contents [1]. Here we present a systematic structural study of the Ni/ZSM-5 materials by Ni
K-edge XANES and EXAFS analyses, to monitor the changes of local structure and chemical state
of Ni species in the catalysts as a function of Al and Ni content. A series of Ni/ZSM-5 type zeolites
with different Al to Si and Ni to Si molar ratios were synthesized by a “green”, template free technique
[2]. With a combination of XAS, XRD and TEM we resolved the changes in the local environment
of Ni species induced by the different Al contents in the
Ni/ZSM-5 catalysts.
Ni species in Ni/ZSM-5 exist as NiO nanocrystals and as
charge compensating Ni2+ cations. The Ni K-edge
XANES and EXAFS results enabled the quantification
of Ni-containing species. At a low Al to Si ratio (nAl/nSi
< 0.04), the NiO nanoparticles predominate in the
samples and account for over 65% of Ni phases.
However, NiO is outnumbered by Ni2+ cations attached
to the zeolite framework in ZSM-5 with a high Al to Si
ratio (nAl/nSi = 0.05) due to a higher number of
framework negative charges imparted by Al. The
obtained results show that the number of highly reducible
and active NiO nanocrystals is strongly correlated with
the framework Al sites present in Ni/ZSM-5 zeolites. |
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| Keywords: | Ni EXAFS, XANES Ni/ZSM-5 catalyst |
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| Publication status: | Published |
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| Publication version: | Version of Record |
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| Year of publishing: | 2024 |
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| Number of pages: | Str. 35 |
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| PID: | 20.500.12556/RUNG-9181-38694527-9d18-75ce-fd95-c5f62f11be9c  |
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| COBISS.SI-ID: | 200920067 |
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| UDC: | 53 |
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| NUK URN: | URN:SI:UNG:REP:Z0VYVTVR |
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| Publication date in RUNG: | 05.07.2024 |
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| Views: | 950 |
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| Downloads: | 3 |
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| Metadata: |    |
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