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Development of a catalyst for epoxidation of methyl esters
Pham, Tien Thanh ; Krajčovič, Jozef (referee) ; Kučerík, Jiří (advisor)
The diploma thesis is focused on the study of heterogeneous catalysts in the epoxidation of rapeseed oil methyl ester. Epoxides of these components have applications in cutting oils, where they could replace hitherto used oils from fossil sources. Epoxidation is a catalyzed reaction using homogeneous catalysts based on mineral acids. However, they have corrosive properties and they are poorly separated after the reaction. However, this work is focused on the study of heterogeneous catalysts in epoxidation. The reaction products were analyzed by GC, SIMDIS and ATR-FTIR. Advanced analytical methods such as ICP-OES, XRF, XRD, SEM, mercury porosimetry and TPR-H2 were used to determine the composition, structural, textural and reducing properties of the catalysts.
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Development of a catalyst for epoxidation of methyl esters
Pham, Tien Thanh ; Krajčovič, Jozef (referee) ; Kučerík, Jiří (advisor)
The diploma thesis is focused on the study of heterogeneous catalysts in the epoxidation of rapeseed oil methyl ester. Epoxides of these components have applications in cutting oils, where they could replace hitherto used oils from fossil sources. Epoxidation is a catalyzed reaction using homogeneous catalysts based on mineral acids. However, they have corrosive properties and they are poorly separated after the reaction. However, this work is focused on the study of heterogeneous catalysts in epoxidation. The reaction products were analyzed by GC, SIMDIS and ATR-FTIR. Advanced analytical methods such as ICP-OES, XRF, XRD, SEM, mercury porosimetry and TPR-H2 were used to determine the composition, structural, textural and reducing properties of the catalysts.
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Polymeric framework materials as noble metal free heterogeneous catalysts
Piatková, Mária ; Bojdys, Michael Janus (advisor) ; Tarábek, Ján (referee)
4 Abstract A functional triazine-based polymer framework with embedded copper (Cu) nanoparticles (Cu@TzP) is obtained from a one-pot, "wet" chemistry process that is easily scaled up to industrial demand. The polymer framework has permanent, guest-accessible microporosity and can be obtained as a membrane with 124 m2 g-1 , or as a bulk powder with 660 m2 g-1 (by Ar sorption). The Cu nanoparticles are generated in situ during the formation process of the polymer framework, and they serve as ideal, heterogenised active sites for C-N bond formation and enzyme-mimetic peroxidase catalysis. Further, we tune the porosity of the polymeric support matrix by thermal tempering (carbonisation). It turns out, that Cu@TzP performs best as a peroxidase-mimic in the form of a thin, accessible flake with 2 nm-sized Cu nanoparticles (NPs). Although no records were broken in terms of catalytic activity, we establish an attractive design principle of a scalable membrane support for noble-metal free catalysis.
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"Ab initio" study of Sn-Ce-O mixed oxides
Fečík, Michal ; Szabová, Lucie (advisor) ; Mazur, Daniel (referee)
The present work is focused on a theoretical analysis based on the numerical DFT+U calcula- tions investigating structural and electronic properties of mixed oxide Sn/CeO2. The main reasons for this study are reported improved catalytic properties of this system that are most probably caused by catalytic properties of cerium oxides, which are based on releasing or (re)capturing of oxygen atoms via the process of cerium oxidation and reduction. In this work we study com- pounds of cerium and tin that compose Sn/CeO2 - that is a metal Sn and CeO2 together with other compounds SnO2 and Ce2O3 - especially by means of band structures and densities of states. Furthermore we studied mixed oxide Sn/CeO2 in terms of electronic structure and morphology. In this work we consider two different modifications of the analyzed system - the first one con- tains oxygen vacancy whereas the second one stay unchanged. Our study is focused on analysis of influence of tin defect upon properties of CeO2, mainly its effect on reduction of cerium atoms. 1
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