4,311 research outputs found
Low temperature CO oxidation on bimetallic structures
No full textTitle: Low temperature CO oxidation on bimetallic structures Author: Petr Hanyš Department: Department of Surface and Plasma Science Supervisor: Doc. RNDr. Václav Nehasil, Dr., Department of Surface and Plasma Science Abstract: Bimetallic system Sn-Rh in the form of the model Sn/Rh(111) system, supported Rh+Sn/Al2O3 and Rh/SnO2 clusters and Rh/SnO2 and Rh+Sn/Al2O3 powder samples was studied using synchrotron radiation photoelectron spectroscopy (SRPES), X-ray photoelectron spectroscopy (XPS), thermal desorption spectroscopy (TDS), molecular beams (MB), transmission and scanning electron microscopy (TEM, SEM), powder X-ray diffraction (XRD) and high pressure reactor within the framework of the study. It was found that formation of Sn-Rh alloy influences catalytic properties of Rh by lowering CO adsorption energy and capacity. It was also found that presence of Rh in this bimetallic system mediates reversible oxidation/reduction of Sn/SnO2, whereas Sn oxide acts as an oxygen reservoir for low temperature CO oxidation. Keywords: bimetallic systems, rhodium, tin, low temperature CO oxidatio
Petr Simon (1944-2018)
No full textThis article is a reflection on the mathematical legacy of Professor Petr Simon.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Analysi
Studium vlivu elektronové struktury na reaktivitu systémů oxid - kov
No full textNázev práce: Studium vlivu elektronové struktury na reaktivitu systémů oxid-kov Autor: Klára Ševčíková Vedoucí práce: doc. RNDr. Václav Nehasil, Dr., Katedra fyziky povrchů a plazmatu Abstrakt Předkládaná práce je zaměřena na studium interakce rhodia a oxidu ceru a její vliv na jejich reaktivitu. Dva druhy systémů, Rh/CeOx a Rh-CeOx, byly charakterizovány pomocí metod fotoelektronové spektroskopie a teplotně programovaných reakcí. Rh/CeOx značí systém složený z rhodiových nanočástic nesených tenkou vrstvou oxidu ceru. V této práci ukazujeme, že dochází k elektronické interakci a přenosu náboje mezi rhodiem a oxidem ceru. Tato interakce závisí na míře redukce oxidu ceru, a přitom značně ovlivňuje reaktivitu celého systému. Rh-CeOx označuje tenké vrstvy oxidu ceru dopované rhodiem. V rámci této práce byly charakterizovány vlastnosti vrstev s různými koncentracemi rhodia. Ukazujeme, že struktura, složení a reaktivita těchto systémů je značně závislá na koncentraci rhodia ve vrstvě oxidu ceru.Title: Study of dependence of the metal-oxide electron structure on the reactivity of these systems Author: Klára Ševčíková Supervisor: doc. RNDr. Václav Nehasil, Dr., Department of Surface and Plasma Science Abstract The presented thesis focuses on studying the interaction between rhodium and cerium oxide and its impact on the reactivity. We investigated two different systems, Rh/CeOx and Rh- CeOx, by means of the photoelectron spectroscopy and the temperature programmed reactions. Rh/CeOx stands for rhodium nanoparticles supported by cerium oxide thin film. We show that there is an electronic metal-substrate interaction between rhodium and cerium oxide. The type of the interaction depends on a degree of cerium oxide reduction and it has a tremendous impact on the reactivity of the system. On the other hand, Rh-CeOx represents cerium oxide thin films doped by rhodium. We characterized the properties of the films with various concentration of rhodium. We show that the morphology, chemical composition and reactivity of the samples strongly depend on the concentration of the rhodium dopant.Katedra fyziky povrchů a plazmatuDepartment of Surface and Plasma ScienceFaculty of Mathematics and PhysicsMatematicko-fyzikální fakult
Study of dependence of the metal-oxide electron structure on the reactivity of these systems
No full textTitle: Study of dependence of the metal-oxide electron structure on the reactivity of these systems Author: Klára Ševčíková Supervisor: doc. RNDr. Václav Nehasil, Dr., Department of Surface and Plasma Science Abstract The presented thesis focuses on studying the interaction between rhodium and cerium oxide and its impact on the reactivity. We investigated two different systems, Rh/CeOx and Rh- CeOx, by means of the photoelectron spectroscopy and the temperature programmed reactions. Rh/CeOx stands for rhodium nanoparticles supported by cerium oxide thin film. We show that there is an electronic metal-substrate interaction between rhodium and cerium oxide. The type of the interaction depends on a degree of cerium oxide reduction and it has a tremendous impact on the reactivity of the system. On the other hand, Rh-CeOx represents cerium oxide thin films doped by rhodium. We characterized the properties of the films with various concentration of rhodium. We show that the morphology, chemical composition and reactivity of the samples strongly depend on the concentration of the rhodium dopant
Centralization of treasury management 2010
No full textThe book consists of five parts: 1. Treasury management and its responsibilities (Chapter 1‐4); 2. Decentralized treasury (Chapter 5); 3. Different phases of the centralization (Chapter 6‐9); 4. Outsourcing (Chapter 10) 5. Regional treasury centres (Chapter 11); 6. Best practices in a bank (Chapter 12); In the first part, the author describes the treasury management focusing on its three core responsibilities, such as assets and liabilities management, cash management, and financial risk management. The second part zooms in on decentralized treasury and decisions about the appropriate degree of centralization/decentralization of the treasury activities. Then we focus on the different phases of the process of centralization, from central interest rate and foreign exchange management through centralization of cash and liquidity management, then transaction processing up to fully centralized treasury. In part four we continue by discussing outsourcing as the next stage following centralization to achieve additional economic benefits. The fifth part contains especially a number of the location criteria, both tax and non‐tax, that must be evaluated during consideration where to establish the regional treasury centre. The last part deals with banking best practices in cash pooling from the point of view of the author that works in one of the top banks in Central and Eastern Europe region
Cyclometalation of phenylpyridines with a ferrocenyl group
No full textNázev práce: Cyklometalace fenylpyridinů s ferrocenylovým substituentem Autor: Bc. Petr Harmach Katedra: Katedra anorganické chemie Vedoucí diplomové práce: prof. RNDr. Petr Štěpnička, Ph.D., DSc. Abstrakt: Cílem této práce byla příprava cyklometalovaných komplexů fenylpyridinů s ferrocenylovým substituentem. Cyklometalované komplexy mají široké spektrum využití, kdy jedním z nejvýznamnějších je použití v katalýze. Připraveny byly iridité a rhodité cyklometalované komplexy s elektrondonorními nebo elektronakceptorními skupinami na pyridinovém kruhu. Všechny tyto látky byly charakterizovány 1 H a 13 C{1 H} NMR spektroskopií, hmotnostní spektrometrií, elementární analýzou a cyklickou voltametrií. U dvou připravených látek byly jejich struktury potvrzeny pomocí metody difrakce rentgenového záření na monokrystalech. Klíčová slova: cyklometalace, pyridin, C-H aktivace, ferrocenTitle: Cyclometalation of phenylpyridines with a ferrocenyl group Author: Bc. Petr Harmach Department: Katedra anorganické chemie Supervisor: prof. RNDr. Petr Štěpnička, Ph.D., DSc. Abstract: The objective of this thesis was the synthesis of cyclometalated complexes of phenylpyridine with a ferrocenyl group. Cyclometalated complexes have a wide range of application, where one of the most important is the use in catalysis. Iridium(III) and rhodium(III) cyclometalated complexes were prepared containing electron-donating or electron-accepting groups on the pyridine ring. All newly prepared complexes were characterized by 1 H a 13 C{1 H} NMR spectroscopy, mass spectrometry, elemetal analysis and cyclic voltammetry. The structures of two complexes were determined by single-crystal X-ray diffraction analysis. Key words: cyclometalation, pyridine, C-H activation, ferroceneDepartment of Inorganic ChemistryKatedra anorganické chemiePřírodovědecká fakultaFaculty of Scienc
Adaptivní volba parametrů stabilizačních metod pro rovnice konvekce-difúze
No full textTitle: Adaptive choice of parameters in stabilization methods for convection- diffusion equations Author: Bc. Petr Lukáš (e-mail: [email protected]) Department: Department of Numerical Mathematics Supervisor: Doc. Mgr. Petr Knobloch, Dr. (e-mail: [email protected]) Abstract: The aim of the work is to propose suitable approaches for adap- tive choice of parameters in stabilization methods for convection-difusion equations discretized by the finite element method. We introduce the L-SR1 method, compare it with other nonlinear methods of minimizing functions with large number of variables, and introduce and compare the adaptive methods based on minimizing of the error indicator. Keywords: Adaptive choice of parameters, finite element method, stabiliza- tion methods, convection-diffusion equation, L-SR1 method, error indicato
Cyclometalation of phenylpyridines with a ferrocenyl group
No full textTitle: Cyclometalation of phenylpyridines with a ferrocenyl group Author: Bc. Petr Harmach Department: Katedra anorganické chemie Supervisor: prof. RNDr. Petr Štěpnička, Ph.D., DSc. Abstract: The objective of this thesis was the synthesis of cyclometalated complexes of phenylpyridine with a ferrocenyl group. Cyclometalated complexes have a wide range of application, where one of the most important is the use in catalysis. Iridium(III) and rhodium(III) cyclometalated complexes were prepared containing electron-donating or electron-accepting groups on the pyridine ring. All newly prepared complexes were characterized by 1 H a 13 C{1 H} NMR spectroscopy, mass spectrometry, elemetal analysis and cyclic voltammetry. The structures of two complexes were determined by single-crystal X-ray diffraction analysis. Key words: cyclometalation, pyridine, C-H activation, ferrocen
Synthesis of gold(I) carbene complexes from isocyanoferrocene
No full textTitle: Synthesis of gold(I) carbene complexes from isocyanoferrocene Author: Petr Harmach Department: Katedra anorganické chemie Supervisor: prof. RNDr. Petr Štěpnička, Ph.D., DSc. Abstract: The objective of this bachelor thesis was the synthesis of gold(I) carbene complexes. These complexes were synthetised from a newly prepared gold(I)-isocyanoferrocene complex and also directly from isocyanoferrocene. Carbene complexes were obtained from primary and secondary amines, and therefore complexes contain disubstituted or trisubstituted diaminocarbene moieties. All newly prepared complexes were characterized by NMR spectroscopy, mass spectrometry, elemental analysis and infrared spectroscopy. The structures of the majority of the prepared complexes were confirmed by single-crystal X-ray diffraction analysis. Key words: isocyanides, ferrocene, carbenes, gold(I) complexe
Homologous ferrocene phosphines
No full textTitle: Homologous ferrocene phosphines Author: Bc. Petr Vosáhlo Department: Department of Inorganic Chemistry Supervisor: prof. RNDr. Petr Štěpnička, Ph.D., DSc. Abstract: This thesis describes the synthesis and coordination behaviour of ferrocene diphosphines derived from 1,1'-bis(diphenylphosphino)ferrocene (dppf). Dppf is one of the most succesful ferrocene ligands, which can be used in various metal-catalyzed reactions. This study aimed to prepare analogous ligands with one dialkylphosphino substituent and one (diphenylphosphino)methyl group. These ligands were oxidized by KSeCN to afford the corresponding phosphinoselenides. The phosphinoselenides were used to assess sigma-donor abilities by measuring the coupling constant 1 JSeP via 31 P NMR spectroscopy. Lastly, the coordination behaviour of these ligands in palladium complexes was studied. The homologous ligands usually formed a mixtures containing a chelate complex and dimeric species with trans- coordinated ligands. Key words: ferrocene, phosphines, homologous ligands, palladium(II) complexes, structure elucidation
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