| Title: | Insight into the interdependence of Ni and Al in bifunctional Ni/ZSM-5 catalysts at the nanoscale |
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| Authors: | ID Vu, Hue-Tong (Author)
ID Arčon, Iztok (Author)
ID Oliveira de Souza, Danilo (Author)
ID Pollastri, Simone (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: |  Hue_Tong_Vu_-_Iztok_Arcon_-_et_al_-__Nanoscale_Advances_2022.pdf (1,25 MB)
MD5: B3C95AD8173A10196CFC134C1B2B3286
 http://repozitorij.ung.si/admin/Datoteka.php?id=24156
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| Language: | English |
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| Work type: | Unknown |
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| Typology: | 1.01 - Original Scientific Article |
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| Organization: | UNG - University of Nova Gorica
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| Abstract: | Catalyst design is crucial for improving catalytic activity and product selectivity. In a bifunctional Ni/ZSM-5
zeolite type catalyst, catalytic properties are usually tuned via varying Al and Ni contents. While changes in
acid properties associated with Al sites are usually closely investigated, Ni phases, however, receive
inadequate attention. Herein, we present a systematic structural study of Ni in the Ni/ZSM-5 materials by
using Ni K-edge XANES and EXAFS analyses, complemented by XRD and TEM, to resolve the changes in
the local environment of Ni species induced by the different Al contents of the parent ZSM-5 prepared
by a “green”, template free technique. Ni species in Ni/ZSM-5 exist as NiO crystals (3–50 nm) 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 ¼ 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 crystals is strongly correlated with the framework Al sites present in
ZSM-5 zeolites, which depend greatly on the synthesis conditions. Therefore, this kind of study is
beneficial for any further investigation of the catalytic activities of Ni/ZSM-5 and other metal-modified
bifunctional catalysts. |
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| Keywords: | Ni/ZSM-5 catalysts, zeolite, Ni XANES, EXAFS |
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| Year of publishing: | 2022 |
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| Number of pages: | str. 1–11 |
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| Numbering: | Vol. , iss. |
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| PID: | 20.500.12556/RUNG-7332  |
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| COBISS.SI-ID: | 107406339 |
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| UDC: | 53 |
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| ISSN on article: | 2516-0230 |
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| DOI: | 10.1039/d2na00102k |
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| NUK URN: | URN:SI:UNG:REP:KOVZZVGE |
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| Publication date in RUNG: | 11.05.2022 |
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| Views: | 1578 |
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| Downloads: | 43 |
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