Master Degree / Yüksek Lisans Tezleri
Permanent URI for this collectionhttps://hdl.handle.net/11147/3008
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Master Thesis Thermal and Photodehydrogenation Reactions of Terpenes Over Zeolites(Izmir Institute of Technology, 2003) Tuzcuoğlu, Esra; Artok, LeventIn this thesis study, catalytic activity of cation exchanged (Na+, Li+, Ca2+, K+, Cs+) zeolite Y, especially NaY, and various microporous and mesoporous (Na exchanged, Beta, Mordenite, and NaX, CsNaX, MCM-41, Montmorillonite KSF and amorphous Silica) catalysts was investigated in the dehydrogenation reaction of terpenes to p-cymene.The results suggested that, there are two types of acid sites are present in cation exchanged zeolites from NH4Y, which are Br Bronsted and Lewis sites. a-terpinene, disproportionated by Br Bronsted acid catalysis into 3-p-menthene and p-cymene, and pcymene was also formed by direct dehydrogenation of a-terpinene can possibly occur with the participation of Lewis acid sites in cation exchanged zeolite Y. Best conversion to p-cymene were observed in the NaHY, LiHY and CaHY exchange from NH4Y that have relatively small cations, which more acidic than the larger ones.With the catalysts that have Bronsted acid sites except ion-exchanged zeolite Y, no conversion or only acid catalyzed isomerization reactions occur that shows the Bronsted acidity was not enough to catalyze the dehydrogenation of a-terpinene. Also Lewis acidic character and the structure morphology are the most important factors affecting the conversion. Lewis acidity is influenced from the cation and zeolite type.Master Thesis Suzuki Reactions Over Palladium Loaded Y Zeolite(Izmir Institute of Technology, 2002) Bulut Güllübağ, Hatice; Artok, LeventIn this study, the use of Pd(II) loaded NaY type zeolite as a catalyst in the Suzukiinvestigated.For this aim, Pd(OAc)2, and [Pd(NH3)4]Cl2 complexes were loaded into NaY zeolite in order to form an appropriate catalyst system. Pd(NH3)42+ loaded Y type zeolite was calcined to obtain Pd(II) form Pd(OAc)2 loaded Y type zeolite showed high activity in the reactions of 4-iodoanisole and 4-bromoanisole with arylboronic acid. However the reusability which is an important property of heterogeneous catalyst could not be provided, the following studies were continued with Pd(II) loaded Y type zeolite.When, 4-iodo and 4-bromoanisole reactives were used in the presence of Pd(II) loaded Y type zeolite, 60-100% biaryl products were obtained. The amount and type of the base and DMF:H2O ratio have high effects on the yield. In order to prove that the reaction took place in heterogeneous phase, at the end of the reaction Pd analysis of the solution was performed by AAS technique. It was found that the Pd amount in solution was trace.