Počet záznamů: 1  

Titanium impregnated borosilicate zeolites for epoxidation catalysis

  1. 1.
    SYSNO ASEP0443285
    Druh ASEPJ - Článek v odborném periodiku
    Zařazení RIVJ - Článek v odborném periodiku
    Poddruh JČlánek ve WOS
    NázevTitanium impregnated borosilicate zeolites for epoxidation catalysis
    Tvůrce(i) Přech, Jan (UFCH-W) RID
    Vitvarová, Dana (UFCH-W) RID
    Lupínková, Lenka (UFCH-W)
    Kubů, Martin (UFCH-W) RID
    Čejka, Jiří (UFCH-W) RID
    Zdroj.dok.Microporous and Mesoporous Materials. - : Elsevier - ISSN 1387-1811
    Roč. 212, AUG 2015 (2015), s. 28-34
    Poč.str.7 s.
    Jazyk dok.eng - angličtina
    Země vyd.NL - Nizozemsko
    Klíč. slovaborosilicate ; titanium impregnation ; epoxidation
    Vědní obor RIVCF - Fyzikální chemie a teoretická chemie
    CEPGAP106/11/0819 GA ČR - Grantová agentura ČR
    Institucionální podporaUFCH-W - RVO:61388955
    UT WOS000355037800004
    EID SCOPUS84926154257
    DOI10.1016/j.micromeso.2015.03.015
    AnotaceTitanium 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%).
    PracovištěÚstav fyzikální chemie J.Heyrovského
    KontaktMichaela Knapová, michaela.knapova@jh-inst.cas.cz, Tel.: 266 053 196
    Rok sběru2016