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Titanium impregnated borosilicate zeolites for epoxidation catalysis
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SYSNO ASEP 0443285 Document Type J - Journal Article R&D Document Type Journal Article Subsidiary J Článek ve WOS Title Titanium impregnated borosilicate zeolites for epoxidation catalysis Author(s) Přech, Jan (UFCH-W) RID
Vitvarová, Dana (UFCH-W) RID
Lupínková, Lenka (UFCH-W)
Kubů, Martin (UFCH-W) RID
Čejka, Jiří (UFCH-W) RID, ORCID, SAISource Title Microporous and Mesoporous Materials. - : Elsevier - ISSN 1387-1811
Roč. 212, AUG 2015 (2015), s. 28-34Number of pages 7 s. Language eng - English Country NL - Netherlands Keywords borosilicate ; titanium impregnation ; epoxidation Subject RIV CF - Physical ; Theoretical Chemistry R&D Projects GAP106/11/0819 GA ČR - Czech Science Foundation (CSF) Institutional support UFCH-W - RVO:61388955 UT WOS 000355037800004 EID SCOPUS 84926154257 DOI 10.1016/j.micromeso.2015.03.015 Annotation Titanium containing molecular sieves, known as effective epoxidation catalysts, can be prepared either by direct synthesis or by post-synthesis impregnation. Controlled incorporation of titanium during the post-synthesis modification can be achieved when titanium atoms are inserted into the framework positions previously occupied by heteroatoms such as boron. In this contribution, we report the post-synthesis incorporation of titanium into borosilicates SSZ-24, SSZ-33, SSZ-42 and CIT-5. Parent borosilicates were deboronated using an HCl solution and subsequently impregnated with titanium (IV) butoxide or titanium (IV) chloride. The character of the titanium active sites was investigated using DR-UV/Vis spectroscopy showing that the titanium was incorporated into the framework positions with tetrahedral coordination. In some samples, other titanium species were present as well. The prepared Ti-SSZ-33 provides high yield of cyclooctene oxide 28.3% (after 240 min at 60 °C in acetonitrile, substrate/catalyst ratio = 10, H2O2 used as oxidant) in comparison with commonly used TS-1 (2.9%). On the other hand, impregnated zeolites SSZ-24, SSZ-42 and CIT-5 provided lower yields of cyclooctene oxide then the TS-1. The materials were found to catalyse the epoxidation of norbornene and linalool as well. The order of catalysts performance was similar for both substrates: Ti-SSZ-33 (norbornene oxide yield 15.4% after 240 min) > Ti-CIT-5 (yield 3.3%) > TS-1(yield 1.8%) > Ti-SSZ-42 (yield 0.8%); Ti-SSZ-33 (linalool oxide yield 13.3% after 320 min) > Ti-CIT-5 (yield 3.6%) > TS-1(yield 3.5%) > Ti-SSZ-42 (yield 1.3%)>Ti-SSZ-24 (yield 0.5%). Workplace J. Heyrovsky Institute of Physical Chemistry Contact Michaela Knapová, michaela.knapova@jh-inst.cas.cz, Tel.: 266 053 196 Year of Publishing 2016
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