Addressing confinement effect in alkenes epoxidation using 'isoreticular' titanosilicate zeolite catalysts
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11310%2F22%3A10451230" target="_blank" >RIV/00216208:11310/22:10451230 - isvavai.cz</a>
Result on the web
<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=8QHoNZRryv" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=8QHoNZRryv</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1016/j.cattod.2021.09.027" target="_blank" >10.1016/j.cattod.2021.09.027</a>
Alternative languages
Result language
angličtina
Original language name
Addressing confinement effect in alkenes epoxidation using 'isoreticular' titanosilicate zeolite catalysts
Original language description
Titanosilicate zeolites are a prominent class of catalysts applied in various oxidation reactions, including epoxidation of alkenes. Numerous studies have been performed to understand the influence of Ti sites structure ('open' vs. 'closed') and their distribution between internal and external surface of zeolite on the catalyst performance, although the effect of Ti location in micropores of different sizes remained unrevealed. Here, we report the application of ADOR synthesis strategy for the preparation of model 'isoreticular' titanosilicate zeolites with the same topology but continuously tunable porosity for addressing the influence of micropore confinement on the activity and selectivity of the catalysts in alkene epoxidation reaction. A set of 'isoreticular' Ti-IPC-n (n = 2, 4, 6, 7) zeolites were synthesized by post-synthesis of Ti-substituted UTL germanosilicate. Structural, textural and acidic properties of the prepared catalysts were characterized by XRD, nitrogen physisorption, FTIR spectroscopy of adsorbed d(3)-acetonitrile, while their activity and selectivity were compared in the epoxidation of 1-hexene and cyclohexene as model linear and cyclic alkenes with hydrogen peroxide as oxidant. The obtained results confirmed the successful preparation of Ti-substituted IPC-n zeolites with similar total concentration of Ti sites (0.15-0.17 mmol/g). For both 1-hexene and cyclohexene epoxidation, the specific activity of a Ti active center (TOF) gradually decreased with the micropore size in a sequence Ti-UTL (TOF(1-hexene) = 126 h(-1); TOF(cyclohexene) = 227 h(-1)) > Ti-IPC-7 (124; 143) > Ti-IPC-2 (124; 130) > Ti-IPC-6 (90; 67) > Ti-IPC-4 (64; 37). In line with reducing diffusion limitations of substrates and products, the site time yield of both targeted epoxides increases with increasing the size of the pores in 'isoreticular' zeolites reaching the maximal value for Ti-UTL (586 and 491 h(-1) for 1,2-epoxyhexane and cyclohexeneoxide, respectively).
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
<a href="/en/project/GX19-27551X" target="_blank" >GX19-27551X: ADORable catalysts</a><br>
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)
Others
Publication year
2022
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Catalysis Today
ISSN
0920-5861
e-ISSN
1873-4308
Volume of the periodical
390
Issue of the periodical within the volume
May
Country of publishing house
NL - THE KINGDOM OF THE NETHERLANDS
Number of pages
9
Pages from-to
326-334
UT code for WoS article
000784303600002
EID of the result in the Scopus database
2-s2.0-85118186620