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dc.contributor.authorGüneş, Alev
dc.contributor.authorBayraktar, Oğuz
dc.contributor.authorYılmaz, Selahattin
dc.date.accessioned2016-10-14T11:04:22Z
dc.date.available2016-10-14T11:04:22Z
dc.date.issued2006-01
dc.identifier.citationGüneş, A., Bayraktar, O., and Yılmaz, S. (2006). Liquid-phase oxidation of carvacrol using zeolite-encapsulated metal complexes. Industrial and Engineering Chemistry Research, 45(1), 54-61. doi:10.1021/ie050185oen_US
dc.identifier.issn0888-5885
dc.identifier.urihttp://doi.org/10.1021/ie050185o
dc.identifier.urihttp://hdl.handle.net/11147/2243
dc.description.abstractWe report here the use of zeolite-encapsulated metal (salpn) complexes as catalysts in the oxidation reaction of the natural compound carvacrol in acetonitrile with hydrogen peroxide as the oxidant. No previous studies on the oxidation of carvacrol in the presence of metal salpn complexes have been reported. By using a general flexible ligand method, Cr(III), Fe(III), Bi(III), Ni(II), and Zn(II) complexes of N,N′-bis(salicylidene)propane1,3-diamine (H2salpn) encapsulated in NaY zeolite were prepared. All catalysts were characterized by Fourier transform infrared (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM) analyses to confirm the complex encapsulation. The activities of all prepared catalysts for the oxidation of carvacrol and hydrogen peroxide were tested. The performances of all catalysts were compared on the basis of the leaching test results and carvacrol conversions. Thymohydroquinone and benzoquinones were observed as byproducts at high conversions of carvacrol. No product was formed in the absence of a catalyst. Fe(salpn)-NaY catalyst exhibited the highest carvacrol conversion of 27.6% with a yield of 22.0%, followed by Cr(salpn)-NaY catalyst with 23.5% carvacrol conversion and a yield of 17.6%. Other catalysts have shown relatively lower performances in terms of carvacrol conversion and leaching. The Cr(salpn)-NaY catalyst was found to be a more efficient catalyst than others on the basis of leaching and activity tests. With the selected catalyst Cr (salpn)-NaY, the effects of temperature and carvacrol/hydrogen peroxide molar ratio on carvacrol oxidation reactions were investigated. Increasing the temperature from 40 to 60 °C caused an increase in the thymoquinone yield from 6.2% to 16.0%. An increase in carvacrol/hydrogen peroxide molar ratio from 1 to 3 resulted in a decrease in the thymoquinone yield.en_US
dc.description.sponsorshipTurkish Scientific Research Council Project MISAG-249 and from the Izmir Institute of Technology Project 2002-IYTE 15en_US
dc.language.isoengen_US
dc.publisherAmerican Chemical Societyen_US
dc.relation.isversionof10.1021/ie050185oen_US
dc.rightsinfo:eu-repo/semantics/openAccessen_US
dc.subjectOxidationen_US
dc.subjectZeolitesen_US
dc.subjectX-ray diffractionen_US
dc.subjectAcetonitrileen_US
dc.subjectHydrogen peroxideen_US
dc.titleLiquid-phase oxidation of carvacrol using zeolite-encapsulated metal complexesen_US
dc.typearticleen_US
dc.contributor.authorIDTR131394en_US
dc.contributor.authorIDTR22592en_US
dc.contributor.iztechauthorGüneş, Alev
dc.contributor.iztechauthorBayraktar, Oğuz
dc.contributor.iztechauthorYılmaz, Selahattin
dc.relation.journalIndustrial and Engineering Chemistry Researchen_US
dc.contributor.departmentİYTE, Mühendislik Fakültesi, Kimya Mühendisliği Bölümüen_US
dc.identifier.volume45en_US
dc.identifier.issue1en_US
dc.identifier.startpage54en_US
dc.identifier.endpage61en_US


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