Fe-ZSM-5 outperforms Al-ZSM-5 in paraffin cracking by increasing the olefinicity of C3-C4 products
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11310%2F24%3A10487016" target="_blank" >RIV/00216208:11310/24:10487016 - isvavai.cz</a>
Result on the web
<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=IcMeXjx8Yo" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=IcMeXjx8Yo</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1016/j.cej.2024.156032" target="_blank" >10.1016/j.cej.2024.156032</a>
Alternative languages
Result language
angličtina
Original language name
Fe-ZSM-5 outperforms Al-ZSM-5 in paraffin cracking by increasing the olefinicity of C3-C4 products
Original language description
Iron-modified Al-ZSM-5 increases selectivity to propene, a key petrochemical resulting from fluid catalytic cracking (FCC). However, the type and role of active iron species remain unclear, hindering efforts to streamline the design of selective FCC additives. Here, we investigated Al-free Fe-ZSM-5 catalysts containing iron species in the form of framework Fe(3+), extra-framework Fe(3+), oxidic clusters, and oxide micro aggregates in n-octane cracking (FCC model) to assess their effect on catalytic cracking. DR-UV-Vis spectroscopy, (57)Fe Mössbauer Spectroscopy, FTIR studies of pyridine adsorption, and n-octane cracking tests at 500 °C revealed that framework-associated coordinatively unsaturated Fe(3+) species, which induce strong Lewis acidity, are responsible for paraffin cracking initiation, whereas bulk iron oxides on the zeolite surface are inactive. In comparison with Al-ZSM-5, Fe-ZSM-5 increases the olefinicity of the valuable C(3)-C(4) fractions (selectivity to propene and butenes) and promotes aromatization reactions due to the lower relative strength of Fe-induced Bronsted acid sites and dehydrogenation properties. As shown by our (57)Fe Mössbauer study (performed at -269 °C) of the catalyst in calcined, spent, and regenerated states, Fe-ZSM-5 deactivation is associated with the loss of tetrahedrally coordinated Fe(3+) species. Therefore, tuning Fe-ZSM-5 C(3)-C(4) selective FCC additives requires stabilizing framework Bronsted and framework-associated Lewis acid sites while decreasing the concentration of iron oxide species. Ultimately, these findings may enable us to meet the demand for propene derived from FCC cracking, which is expected to grow in the foreseeable future.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10403 - Physical chemistry
Result continuities
Project
Result was created during the realization of more than one project. More information in the Projects tab.
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)<br>I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace
Others
Publication year
2024
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Chemical Engineering Journal
ISSN
1385-8947
e-ISSN
1873-3212
Volume of the periodical
499
Issue of the periodical within the volume
November
Country of publishing house
CH - SWITZERLAND
Number of pages
14
Pages from-to
156032
UT code for WoS article
001327754400001
EID of the result in the Scopus database
2-s2.0-85204936203