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Residential House in Prague 6
Čejka, Jiří ; Jeneš, Rostislav (referee) ; Podroužková, Božena (advisor)
The thesis called Block of Flats in Prague 6 is composed as a project documentation of the static part. This six-level building was designed as a ferroconcrete monolithic object. Two underground floors are formed by a ferroconcrete frame with columns. There are placed parking slots and also a residential section on these two floors. Four other levels are designed as a ferroconcrete frame with walls. These four floors serve as a residential section. The thesis deals with the complete design of the first floor of one structural unit of the building, and also with some details such as floor slab, bearers, staircase, columns, and walls.
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Preparation and characterization of new materials for metathesis and adsorption
Pastva, Jakub ; Čejka, Jiří (advisor) ; Gyepes, Róbert (referee) ; Koubek, Josef (referee)
The main objective of this work was to evidence versatile applications of ordered siliceous mesoporous materials, especially in adsorption and catalysis. For these reasons four mesoporous molecular sieves (SBA-15, SBA-16, MCM-41, and MCM-48) with different structures and textural properties have been chosen. To show the possible application of mesoporous molecular sieves as a CO2 adsorbent, magnesium oxide, and potassium carbonate were incorporated into SBA-15, SBA-16, and MCM-48 silicas. In order to avoid destruction of silica supports, a novel procedure based on the precipitation of magnesium acetate on the silica surface was developed. Subsequent in situ chemical conversion of magnesium acetate provided magnesium oxalate, while magnesium oxide was formed by calcination. To introduce potassium carbonate, silica modified with MgO was impregnated with potassium oxalate followed by its conversion to carbonate. All prepared mesoporous adsorbents preserved characteristic features of mesoporous molecular sieve (large surface areas, narrow pore size distributions). The comparison of carbon dioxide isotherms obtained on prepared samples revealed that their adsorption properties are influenced by the type of mesoporous structure. The SBA-15 silica containing magnesium oxide and promoted by potassium...
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Metal nanoparticles in zeolites
Zhang, Yuyan ; Čejka, Jiří (advisor) ; Zima, Vítězslav (referee) ; Kubička, David (referee)
Zeolites with encapsulated metal nanoparticles have attracted a wide attention in heterogeneous catalysis due to their high catalytic activity, selectivity, and stability. The PhD thesis was focused on design and synthesis of metal@zeolite catalysts with small and uniformly distributed metal nanoparticles. The main interests were encapsulation of metal nanoparticles into zeolites by co-crystallization strategy and 2-dimensional to 3-dimensional zeolite transformation approach. The PhD work was performed at the Department of Synthesis and Catalysis at J. Heyrovský Institute of Physical Chemistry and Department of Physical and Macromolecular Chemistry, Faculty of Science at Charles University under the supervision of Prof. Jiří Čejka. Zeolites are inorganic crystalline aluminosilicates with microporous framework structures. The micropores of zeolites provide the ideal microenvironment to accommodate metal nanoparticles. During metal nanoparticles formation in zeolite micropores, they can be limited by a rigid framework, preventing the aggregation and leaching of metal during the reaction process. Furthermore, the diameters of zeolite micropores are usually in the range of 0.3-1.5 nm, which can be used to discriminate molecules depending on their size and shape, thus endowing the metal@zeolite...
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Chemistry of the Interlamellar Space of Two-dimensional Zeolites
Mazur, Michal ; Čejka, Jiří (advisor) ; Zima, Vítězslav (referee) ; Hronec, Mlan (referee)
The presented PhD thesis is focused on the synthesis, characterization, and modifications of zeolites and zeolitic materials. The main interests are two-dimensional (2D) zeolites and modification of their interlamellar space. Presented work was performed at the Department of Synthesis and Catalysis at J. Heyrovský Institute of Physical Chemistry in Prague, Czech Republic under the supervision of Prof. Jiří Čejka. Zeolites are inorganic crystalline solids with a microporous framework structure. They are widely used as catalysts, sorbents, and ion-exchangers. Conventional zeolites have been recognized as three-dimensional (3D) tetrahedrally-connected frameworks. However, some of them are also known to exist in various layered forms (2D zeolites). Recently, the transformation of 3D germanosilicate UTL into layers (IPC-1P) has started a new branch in 2D zeolites chemistry. This chemically selective degradation of UTL framework was performed via acid hydrolysis. In the structure of this germanosilicate, Ge atoms are preferentially located in specific building units, double-four-rings (D4R), which connect dense silica layers. Modifications of the layered precursor IPC-1P led to discovery of the two novel 3D zeolites: IPC-4 (PCR) and IPC-2 (OKO). This novel approach in the zeolite synthesis, called ADOR...
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Synthesis and Post-synthesis Modification of Novel 2-Dimensional Zeolites
Přech, Jan ; Čejka, Jiří (advisor) ; Bulánek, Roman (referee) ; Hronec, Mlan (referee)
Development of sustainable and environmentally friendly chemical processes is of vital importance nowadays. Although there is a palette of different synthetic methods for the formation of epoxides, sulphoxides and sulphones, from both economic and environmental points of view, a direct oxidation with a simple oxidant is highly appreciated. The main goals of the thesis were design and synthesis of novel titanium containing zeolitic materials with the ability to catalyse selective oxidation of sterically demanding organic compounds, particularly epoxidation of cyclic olefins and terpenes and oxidation of bulky thioethers to corresponding sulphoxides and sulphones with hydrogen peroxide as the oxidant. Two novel extra-large pore titanosilicates were prepared by means of hydrothermal synthesis (Ti-CFI, Ti-UTL), three large-pore titanosilicates (Ti-CON, Ti-AFI, Ti-IFR) were prepared using two step deboronation - liquid phase titanium impregnation procedure and two groups of lamellar materials were prepared. One group was based on modified nanosheet TS-1; the other was prepared from Ti-IPC- 1P lamellar precursor, which was prepared by means of top-down transformation of Ti-UTL. Last but not least, the Ti-UTL was transformed into new titanosilicates Ti-IPC-2 (OKO structure) and Ti-IPC-4 (PCR structure) by...
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Synthesis, characterization and catalytic application of novel zeolites
Eliášová, Pavla ; Čejka, Jiří (advisor) ; Štěpnička, Petr (referee) ; Mintova, Svetlana (referee)
The PhD thesis concerns the synthesis of novel zeolite materials, investigation of their properties and their possible use in catalytic application. The work was focused on the two- dimensional zeolites. The thesis was worked out at the Department of Synthesis and Catalysis at J. Heyrovský Institute of Physical Chemistry, AS CR. Germanosilicate UTL (Si/Ge molar ratio 4.0-6.5) was found to undergo unique structural changes in the neutral or acid environment leading to transformation of its three-dimensional framework into two-dimensional layered material denoted IPC-1P. The UTL degradation, so called top-down synthesis, was enabled due to a presence of double-four-units (D4Rs), which can be seen as supporting units/pillars between the rigid layers. The preferential location of Ge in D4Rs makes the units an ideal target for their selective degradation. The interlayer space in lamellar IPC-1P was modified by swelling with long-organic chain surfactant (material IPC-1SW). To keep the interlayer space permanently expanded (up to 3.3 nm) the silica amorphous pillars were subsequently introduced (material IPC-1PI). The integrity of the layers and their preserved UTL character was confirmed in all members of IPC-1 family by HRTEM and electron diffraction measuring. The layers of IPC-1P were condensed back...
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Theoretical Investigation of Friedlander Reaction catalyzed by CuBTC
Položij, Miroslav ; Nachtigall, Petr (advisor) ; Čejka, Jiří (referee)
The mechanism of Friedlander reaction was investigated theoretically. The main objective was to find a reaction path of Friedlander reaction catalyzed by Cu3(BTC)2 (BTC = benzene-1,3,5-tricarboxylic acid), a microporous metal organic framework. In addition, possible mechanisms of non-catalyzed and acid-catalyzed reaction were investigated in the gas phase and in the solution. The suitability of Cu3(BTC)2 as catalyst for Friedlander reaction is discussed based on the computational results obtained.
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Preparation and characterization of new materials for metathesis and adsorption
Pastva, Jakub ; Čejka, Jiří (advisor) ; Gyepes, Róbert (referee) ; Koubek, Josef (referee)
The main objective of this work was to evidence versatile applications of ordered siliceous mesoporous materials, especially in adsorption and catalysis. For these reasons four mesoporous molecular sieves (SBA-15, SBA-16, MCM-41, and MCM-48) with different structures and textural properties have been chosen. To show the possible application of mesoporous molecular sieves as a CO2 adsorbent, magnesium oxide, and potassium carbonate were incorporated into SBA-15, SBA-16, and MCM-48 silicas. In order to avoid destruction of silica supports, a novel procedure based on the precipitation of magnesium acetate on the silica surface was developed. Subsequent in situ chemical conversion of magnesium acetate provided magnesium oxalate, while magnesium oxide was formed by calcination. To introduce potassium carbonate, silica modified with MgO was impregnated with potassium oxalate followed by its conversion to carbonate. All prepared mesoporous adsorbents preserved characteristic features of mesoporous molecular sieve (large surface areas, narrow pore size distributions). The comparison of carbon dioxide isotherms obtained on prepared samples revealed that their adsorption properties are influenced by the type of mesoporous structure. The SBA-15 silica containing magnesium oxide and promoted by potassium...
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