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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Development and Synthetic Application of N-Boc-Protected Aminals as the Precursors of N-Boc-Protected Imines / Boc保護イミン前駆体としてのBoc保護アミナールの開発と合成反応への応用

Yurino, Taiga 23 May 2013 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第17773号 / 理博第3896号 / 新制||理||1562(附属図書館) / 30580 / 京都大学大学院理学研究科化学専攻 / (主査)教授 丸岡 啓二, 教授 大須賀 篤弘, 教授 時任 宣博 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM
2

Catalytic reactions of organic compounds by titanium oxides and titanate nanotubes / 酸化チタンおよびチタン酸ナノチューブを触媒とした有機化学反応

Wada, Emiko 23 March 2017 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(人間・環境学) / 甲第20475号 / 人博第825号 / 新制||人||197(附属図書館) / 28||人博||825(吉田南総合図書館) / 京都大学大学院人間・環境学研究科相関環境学専攻 / (主査)教授 吉田 寿雄, 教授 内本 喜晴, 教授 田部 勢津久, 教授 加藤 立久 / 学位規則第4条第1項該当 / Doctor of Human and Environmental Studies / Kyoto University / DFAM
3

Acid monolayer functionalized iron oxide nanoparticle catalysts

Ikenberry, Myles January 1900 (has links)
Doctor of Philosophy / Department of Chemical Engineering / Keith L. Hohn / Superparamagnetic iron oxide nanoparticle functionalization is an area of intensely active research, with applications across disciplines such as biomedical science and heterogeneous catalysis. This work demonstrates the functionalization of iron oxide nanoparticles with a quasi-monolayer of 11-sulfoundecanoic acid, 10-phosphono-1-decanesulfonic acid, and 11-aminoundecanoic acid. The carboxylic and phosphonic moieties form bonds to the iron oxide particle core, while the sulfonic acid groups face outward where they are available for catalysis. The particles were characterized by thermogravimetric analysis (TGA), transmission electron microscopy (TEM), potentiometric titration, diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), inductively coupled plasma optical emission spectrometry (ICP-OES), X-ray photoelectron spectrometry (XPS), and dynamic light scattering (DLS). The sulfonic acid functionalized particles were used to catalyze the hydrolysis of sucrose at 80˚C and starch at 130˚C, showing a higher activity per acid site than the traditional solid acid catalyst Amberlyst-15, and comparing well against results reported in the literature for sulfonic acid functionalized mesoporous silicas. In sucrose catalysis reactions, the phosphonic-sulfonic nanoparticles (PSNPs) were seen to be incompletely recovered by an external magnetic field, while the carboxylic-sulfonic nanoparticles (CSNPs) showed a trend of increasing activity over the first four recycle runs. Between the two sulfonic ligands, the phosphonates produced a more tightly packed monolayer, which corresponded to a higher sulfonic acid loading, lower agglomeration, lower recoverability through application of an external magnetic field, and higher activity per acid site for the hydrolysis of starch. Functionalizations with 11-aminoundecanoic acid resulted in some amine groups binding to the surfaces of iron oxide nanoparticles. This amine binding is commonly ignored in iron oxide nanoparticle syntheses and functionalizations for biomedical and catalytic applications, affecting understandings of surface charge and other material properties.
4

Application of Metal Nanoparticles and Polyoxometalates for Efficient Photocatalysis and Catalysis / 高効率光触媒および触媒反応のための金属ナノ粒子およびポリオキソメタレートの利用

Iwase, Yukari 26 March 2018 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第21118号 / 工博第4482号 / 新制||工||1696(附属図書館) / 京都大学大学院工学研究科物質エネルギー化学専攻 / (主査)教授 阿部 竜, 教授 安部 武志, 教授 作花 哲夫 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM
5

Produção de biodiesel a partir de óleo residual reciclado e realização de testes comparativos com outros tipos de biodiesel e proporções de mistura em um moto-gerador

Dib, Fernando Henrique [UNESP] 26 February 2010 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:23:39Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-02-26Bitstream added on 2014-06-13T20:50:43Z : No. of bitstreams: 1 dib_fh_me_ilha.pdf: 1753088 bytes, checksum: 6f21fa7a5002d96add683e1ad3d75eb9 (MD5) / Neste trabalho são analisadas técnicas de produção do biodiesel a partir do óleo residual reciclado, visando a diversificação da matriz energética brasileira e minimização dos impactos ambientas decorrentes do descarte inadequado desses óleos. Antes do início da produção de biodiesel é necessária a realização de um pré-tratamento deste óleo, o que envolve processos de filtragem, secagem e determinação do teor de acidez, seguida de neutralização, pois de acordo com a porcentagem de ácidos graxos livres presentes na matéria-prima é que os métodos para obtenção dos ésteres são adotados. Primeiramente, foram realizados testes laboratoriais em pequena escala para produção de biodiesel, utilizando como matérias prima o óleo residual reciclado e o óleo de soja degomado para efeito comparativo, tendo sido utilizado hidróxido de sódio como catalisador e experimentadas as rotas metílica e etílica, não tendo sido obtidos resultados satisfatórios neste último caso. Em seguida, a produção foi expandida para uma escala semi-piloto, através da utilização de um reator com capacidade de produzir entre 75 e 80 litros de biodiesel por batelada, sendo neste caso utilizado apenas óleo residual reciclado e processo de transesterificação através da rota metílica, tendo o hidróxido de sódio como catalisador. Depois disso, foi feita a caracterização básica do biodiesel produzido, utilizando-se os equipamentos disponíveis, e foram realizados testes comparativos com outros tipos de biodiesel (Comercial, Vegetal e Animal) e frações de misturas (B25, B50, B75 e B100), tendo como base o biodiesel comercial (B5). Por fim, foram feitos testes com esses combustíveis em um moto-gerador diesel de 6 kVA, variando-se a carga de 0 a 3 kW e determinando-se o consumo específico e a temperatura dos gases de exaustão... / This study analyzes the technical production of biodiesel from waste oil recycling, aimed at diversifying the Brazilian energy matrix and minimizing the environmental impacts of inadequate disposal of waste oils. Before the production of biodiesel it is necessary to perform a previous treatment of this oil, which involves processes of filtration, drying and determination of acidity, followed by neutralization, because according to the percentage of free fatty acids present in the raw material is that the methods for obtaining the esters are defined. Firstly, laboratory tests were performed on a small scale biodiesel production using raw materials like soybean oil and recycle waste soybean oil for comparison, having been used sodium hydroxide as catalyst and tested methyl and ethyl routes, being no obtained satisfactory results in this last case. Then, the production was expanded to a semi-pilot scale, using a reactor that can produces between 75 and 80 liters of biodiesel per batch, being in which case only used recycle waste oil and the transesterification process using methanol route, with sodium hydroxide as catalyst. After that, a basic characterization of biodiesel had been done, using equipment available, and were conducted comparative tests with other types of biodiesel (commercial, vegetable and animal) and fractions of blends (B25, B50, B75 and B100), with commercial biodiesel like base of comparison (B5). Finally, tests were performed with these fuels in a 6 kVA diesel generator set, varying a resistive load from 0 to 3 kW and determining the specific consumption and temperature of the exhaust gases. Analyzing the results, it was verified that the physical and chemical properties measured are within acceptable limits, with density between 0,871 and 0,910 g/ml, viscosity between 3,9 and 6,1 cSt and flash point between 51 and 183°C,... (Complete abstract click electronic access below)
6

Produção de biodiesel a partir de óleo residual reciclado e realização de testes comparativos com outros tipos de biodiesel e proporções de mistura em um moto-gerador /

Dib, Fernando Henrique. January 2010 (has links)
Orientador: Ricardo Alan Verdu Ramos / Banca: Antonio João Diniz / Banca: Marcio Higa / Resumo: Neste trabalho são analisadas técnicas de produção do biodiesel a partir do óleo residual reciclado, visando a diversificação da matriz energética brasileira e minimização dos impactos ambientas decorrentes do descarte inadequado desses óleos. Antes do início da produção de biodiesel é necessária a realização de um pré-tratamento deste óleo, o que envolve processos de filtragem, secagem e determinação do teor de acidez, seguida de neutralização, pois de acordo com a porcentagem de ácidos graxos livres presentes na matéria-prima é que os métodos para obtenção dos ésteres são adotados. Primeiramente, foram realizados testes laboratoriais em pequena escala para produção de biodiesel, utilizando como matérias prima o óleo residual reciclado e o óleo de soja degomado para efeito comparativo, tendo sido utilizado hidróxido de sódio como catalisador e experimentadas as rotas metílica e etílica, não tendo sido obtidos resultados satisfatórios neste último caso. Em seguida, a produção foi expandida para uma escala semi-piloto, através da utilização de um reator com capacidade de produzir entre 75 e 80 litros de biodiesel por batelada, sendo neste caso utilizado apenas óleo residual reciclado e processo de transesterificação através da rota metílica, tendo o hidróxido de sódio como catalisador. Depois disso, foi feita a caracterização básica do biodiesel produzido, utilizando-se os equipamentos disponíveis, e foram realizados testes comparativos com outros tipos de biodiesel (Comercial, Vegetal e Animal) e frações de misturas (B25, B50, B75 e B100), tendo como base o biodiesel comercial (B5). Por fim, foram feitos testes com esses combustíveis em um moto-gerador diesel de 6 kVA, variando-se a carga de 0 a 3 kW e determinando-se o consumo específico e a temperatura dos gases de exaustão... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This study analyzes the technical production of biodiesel from waste oil recycling, aimed at diversifying the Brazilian energy matrix and minimizing the environmental impacts of inadequate disposal of waste oils. Before the production of biodiesel it is necessary to perform a previous treatment of this oil, which involves processes of filtration, drying and determination of acidity, followed by neutralization, because according to the percentage of free fatty acids present in the raw material is that the methods for obtaining the esters are defined. Firstly, laboratory tests were performed on a small scale biodiesel production using raw materials like soybean oil and recycle waste soybean oil for comparison, having been used sodium hydroxide as catalyst and tested methyl and ethyl routes, being no obtained satisfactory results in this last case. Then, the production was expanded to a semi-pilot scale, using a reactor that can produces between 75 and 80 liters of biodiesel per batch, being in which case only used recycle waste oil and the transesterification process using methanol route, with sodium hydroxide as catalyst. After that, a basic characterization of biodiesel had been done, using equipment available, and were conducted comparative tests with other types of biodiesel (commercial, vegetable and animal) and fractions of blends (B25, B50, B75 and B100), with commercial biodiesel like base of comparison (B5). Finally, tests were performed with these fuels in a 6 kVA diesel generator set, varying a resistive load from 0 to 3 kW and determining the specific consumption and temperature of the exhaust gases. Analyzing the results, it was verified that the physical and chemical properties measured are within acceptable limits, with density between 0,871 and 0,910 g/ml, viscosity between 3,9 and 6,1 cSt and flash point between 51 and 183°C,... (Complete abstract click electronic access below) / Mestre
7

Reactivity of Aluminium chlorofluoride (ACF) towards C−F bond activations and C−F bond formations

Kervarec, Maëva-Charlotte 06 October 2021 (has links)
Der Fokus dieser Dissertation lag in der Untersuchung des Potentials von Aluminium-chlorofluorid (ACF) als Katalysator für die Synthese von fluorierten Verbindungen. Insbesondere die C−F-Aktivierung von verschiedenen polyfluorierten Stoffen wurde untersucht, welches die Effizienz des festen Lewis-Säure-Katalysators für diesen Reaktionstyp zeigte. Das potente Treibhausgas 2-Chlor-1,1,1,2-tetrafluorpropan wurde erfolgreich in das dehydrofluorierte Produkt. Weiterhin wurden Umsetzungen von Pentafluorpropan-Isomeren wie z.B. 1,1,1,3,3-Pentafluorpropan, 1,1,1,2,2-Pentafluorpropan und 1,1,1,2,3-Pentafluorpropan mit ACF als Katalysator untersucht. Es konnte gezeigt werden, dass die Aktivierung der primären CH2F-Gruppe in schnell stattfindet und dabei keine Wasserstoffquelle erfordert. Im Kontrast dazu, wurde für die Aktivierung von CF2-Gruppen eine Wasserstoffquelle wie etwa HSiEt3 benötigt und resultierte in der Bildung eines Produktgemischs. Alternativ wurden Hydrofluorierungsreaktionen von mehreren Substraten durch die Synthese und den Einsatz eines neuen Materials erreicht, welches auf der Immobilisierung von HF auf der Oberfläche von ACF beruht. Dieses HF-ACF wurde unter der Verwendung von vielfältigen Charakterisierungsmethoden umfassend untersucht. Die innere Struktur des Festkörpers, wurden mit MAS-NMR-Spektroskopie, FTIR, Inelastische Neutronenstreuung, XRD und Thermoanalyse analysiert Dadurch konnte gezeigt werden, dass eine geringfügige Reorganisation des bulks zu einer besser geordneten Matrix und die Bildung einer mit der ACF-Oberfläche wechselwirkenden Polyfluorid-Struktur vorliegt. Zur Bestimmung der Oberflächengröße wurde das BET-Modell genutzt und zur Analyse der Porengröße wurde die NLDFT verwendet. Abschließend wurden verschiedene Probeverbindungen an der Oberfläche des HF-ACFs adsorbiert um die Azidität der Oberfläche zu bestimmen und es konnte gezeigt werden, dass eine signifikante Reduktion der Lewis- und Brønsted-Azidität vorliegt. / The main focus of this thesis lies in the study of the potential of aluminum chlorofluoride (ACF) as a catalyst for the synthesis of fluorinated compounds. In particular, C−F bond activations of various polyfluorinated compounds were studied, showing the efficiency of this solid Lewis acid catalyst for this type of reaction. The potent greenhouse gas 2-chloro-1,1,1,2-tetrafluoropropane was successfully transformed into the dehydrofluorination product 2-chloro-3,3,3-trifluoropropene under mild conditions. Similarly, transformation of pentafluoropropane isomers, such as 1,1,1,3,3-pentafluoropropane, 1,1,1,2,2- pentafluoropropane and 1,1,1,2,3-pentafluoropropane was also investigated using ACF as a catalyst. It was evidenced that the primary CH2F group present in 1,1,1,2,3-pentafluoropropane was easily activated without the need for a hydrogen source. In contrast, to activate CF2 groups, a hydrogen source such as HSiEt3 was required, generating a variety of products. Alternatively, successful hydrofluorination reactions of several substrates were conducted by synthesizing a new material, based on the loading of hydrogen fluoride (HF) at the surface of ACF. This HF-loaded ACF was deeply studied using a wide range of characterization methods. For the bulk, MAS NMR spectroscopy, Fourier Transform Infrared spectroscopy (FTIR), Inelastic Neutron Scattering (INS), Powder X-Ray Diffraction (P-XRD), and thermoanalysis were performed, revealing a slight reorganization of the bulk towards a better-ordered matrix and the formation of polyfluoride structure interacting with the surface of ACF. The BET model was used for the surface area determination, and the pore size analysis was established using the non local density functional theory (NLDFT). Finally, various probe molecules were adsorbed at the surface of HF-loaded ACF to determine the acidity of the surface, revealing a significantly reduced Lewis and Brønsted acidity.
8

Synthesis And Characterization Of Water Soluble Polymer Stabilized Transition Metal(0) Nanoclusters As Catalyst In Hydrogen Generation From The Hydrolysis Of Sodium Borohydride And Ammonia Borane

Metin, Onder 01 December 2010 (has links) (PDF)
Metal nanoclusters exhibit unique properties which differ from their bulk materials, owing to the quantum size effects. For example, the catalytic activity of transition metal nanoclusters generally increases with decreasing particle size. However, nanoclusters tend to be fairly unstable with respect to the agglomerate into bulk metal in solution and thus special precautions have to be taken to avoid their aggregation or precipitation during the preparation of such nanoclusters in solution. In order to obtain stable nanoclusters dispersed in solution, a stabilizing agent is usually added into the reaction system. The stabilization of metal nanoclusters in solution can be achieved either by electrostatically by using charged ions such as acetate ion or sterically by long chain molecules such as polymers. Polymers are one of the most widely used steric stabilizers for the preparation of stable metal nanoclusters in solution. The use of polymers as stabilizer for the synthesis of transition metal nanoclusters provides advantegous regarding solubility, conductivity, thermal stability and reusability. The metal nanoclusters stabilized by polymers generally show higher catalytic activity, stability and optical properties. In this dissertation we report the preparation and characterization of water soluble polymer stabilized transition metal(0) (metal= Ni, Co and Ru) nanoclusters and their v catalysis in hydrogen generation from the hydrolysis of sodium borohydride (NaBH4) and ammonia borane (AB) which are the best candidates as chemical hydrogen storage materials for on-board applications. The water soluble polymer stabilized nickel(0), cobalt(0) and ruthenium(0) nanoclusters were prepared by using two different facile methods / (i) the reduction of metal precursors by sodium borohydride in the presence poly(N-vinyl pyrrolidone) (PVP) in methanol solution after 1h reflux, (ii) the in situ generation during the hydrolysis of ammonia borane in the presence of poly(4-styrene sulfonicacid-co-maleic acid) (PSSA-co-MA). The characterization of both type of polymer stabilized transition metal(0) nanoclusters were done by using UV-Visible electronic absorption spectroscopy (UV-Vis), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and FT-IR techniques. The catalytic activity of PVP stabilized nickel(0), cobalt(0) and ruthenium(0) nanoclusters was tested in the hydrolysis of NaBH4 and AB. The catalytic acitivity of PSSA-co-MA stabilized nickel(0), cobalt(0) and ruthenium(0) nanoclusters was tested only in the hydrolysis of AB in which they were in situ generated. The kinetics of hydrogen generation from both hydrolysis reactions in the presence PVP or PSSA-co-MA stabilized nickel(0), cobalt(0) and ruthenium(0) nanoclusters were studied depending on the polymer to metal ratio, catalyst concentration, substrate concentration and temperature as well as the activation parameters (Arrhenius activation energy (Ea), activation enthalpy (

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