Background: Indoor air pollution due to the burning of biomass fuels has been associated with acute respiratory infections amongst children less than five years old in developing countries. Very little is known about the relationship between child indoor pollution exposure and time spent near indoor fires. Aim: To describe the relationship between the amount of time that children spend close to indoor fires and carbon monoxide exposure. Methods: Cross-sectional study based in rural North-West of South Africa. Secondary analysis of caregivers’ estimates of their children’s time-activity budgets and children’s exposure to carbon monoxide (N=100). Results: The time spent by children near indoor fires is non-significantly related to their CO exposure (regression coefficient -0.030 to -0.036) after adjusting for explanatory variables. Conclusion: It is important to be cautious about encouraging caregivers to keep children away from indoor fires at the expense of other established intervention strategies.

Este trabalho teve como objetivo sintetizar eletrólitos híbridos de Nafion-TiO2 e eletrocatalisadores de PtSn/C para a aplicação em células a combustível de oxidação direta de etanol (DEFC) em alta temperatura (130oC). Para tanto, partículas de TiO2 foram incorporadas in-situ em membranas comerciais de Nafion via processo sol-gel. Os materiais resultantes foram caracterizados por análise gravimétrica, absorção de água, DSC, DRX e EDX. Eletrocatalisadores baseados em platina-estanho dispersos em carbono (PtSn/C), de diferentes composições, foram produzidos pelo método de redução por álcool e utilizados como eletrodos anódicos. Os eletrocatalisadores foram caracterizados por DRX, EDX, XPS e MET. A avaliação eletroquímica dos eletrocatalisadores foi realizada por voltametria cíclica, varredura linear anódica de monóxido de carbono (stripping de CO) e cronoamperometria. Ânodos de PtSn/C e cátodos de Pt/C comercial foram dispostos juntamente com os híbridos Nafion-TiO2 para a formação do conjuntos membrana-eletrodos. A avaliação final dos materiais foi realizada por meios de curvas de polarização em células unitárias alimentadas com misturas padrão H2/CO ou etanol no ânodo e com oxigênio no cátodo no intervalo de temperatura de 80 a 130oC. As análises demonstraram que o uso de membranas híbridas diminuiu o crossover de combustível, melhorando o desempenho da célula e que o eletrocatalisador PtSn/C 70:30, produzido pelo método de redução por álcool, foi o que demonstrou melhor desempenho para oxidação de etanol. / In this work, Nafion-TiO2 hybrid electrolytes and PtSn/C electrocatalysts were synthesized for the application in direct ethanol fuel cell operating at high temperature (130oC). For this purpose, TiO2 particles were incorporated in commercial Nafion membranes by an in situ sol gel route. The resulting materials were characterized by gravimetric analysis, water uptake, DSC, XRD and EDX. Electrocatalysts based on carbon dispersed platinum-tin (PtSn/C), with different composition, were produced by alcohol-reduction method and were employed as anodic electrode. The electrocatalysts were characterized by XRD, EDX, XPS and transmission electronic spectroscopy. The electrochemical characterization was conducted by cyclic voltametry, carbon monoxide linear anodic voltammetry (CO stripping), and chronoamperometry. Membrane-electrodes assembly (MEAs) were formed with PtSn/C anodes, Pt/C cathodes and Nafion-TiO2 hybrids. The performance of these MEA was evaluated in single-cell fed with H2/CO mixture or ethanol solution at the anode and oxygen at the cathode in the temperature range of 80-130oC. The analysis showed that the hybrid membranes improved the DEFC performance due to crossover suppression and that PtSn/C 70:30 electrocatalysts, prepared by an alcohol reduction process, showed better performance in ethanol oxidation.

Oxidação de CO dissolvido em Pt(111) e Pt(110) foi realizada em soluções de ácido sulfúrico e perclórico em eletrodo rotatório em configuração de menisco (HMRDE). O uso de diferentes soluções eletrolíticas revelou a influência do anion na cinética de oxidação. Uma vez oxidada a camada de CO adsorvido, ânions podem adsorver na superfície do eletrodo provocando mudanças na corrente estacionária em potenciais anódicos. Na varredura negativa, os ânions adsorvidos são deslocados da superfície quando a velocidade de oxidação de CO é menor que a velocidade de adsorção de CO. A carga associada a esse deslocamento foi obtida para altas velocidades de varredura, resultado semelhante aos experimentos de deslocamento espécies adsorvidas só que a baixos potenciais. A oxidação de CO dissolvido também foi realizada em superfícies escalonadas pertencente à série Pt(s)[n(111)×(111)] usando a mesma configuração dos experimentos com eletrodos de baixo índice de Miller em solução de ácido sulfúrico. O perfil voltamétrico não foi significantemente modificado pela presença de defeitos (degraus). No entanto, as curvas são deslocadas para potencias negativos com o aumento da densidade de degraus. Assim, na varredura positiva, foi observada uma relação linear do potencial de inicio de oxidação (pico de ignição) e a densidade de degraus para os eletrodos com terraços de largura superior a 5 átomos de Pt. Na varredura negativa, o mesmo comportamento foi observado no potencial onde a reação não é mais favorecida. Neste caso, o eletrodo de Pt(111) mostrou um comportamento distinto das superfícies escalonadas, devido a formação e uma ordenada camada de (bi)sulfato adsorvido O processo de adsorção de ânion foi também observada na varredura negativa sob altas velocidades de varredura, com cargas relacionadas a dessorção do ânion similares a Pt(111). Apenas para o eletrodo com terraços de largura de 3 átomos mostrou valores similares a Pt(110). Todos os resultados foram analisados em função do mecanismo de reação e o possível efeito dos degraus na formação da camada de adsorção de CO. Para finalizar, um modelo para a oxidação de CO dissolvido foi proposto usando para isso equações diferenciais que descrevem o comportamento dos processos envolvidos na reação de oxidação. Através das voltametrias cíclicas obtidas pelas simulações foi possível investigar o papel da camada de adsorção de CO, a variação das constantes de velocidade das reações envolvidas e as condições do transporte de massa na resposta eletroquímica. Os resultados mostraram que a oxidação de CO dissolvido é um processo complexo com um delicado balanço das velocidades de reações envolvidas, e o deslocamento de ânions contribui para a velocidade da reação global. / Bulk CO oxidation experiments have been carried out in sulphuric and perchloric acid solutions on Pt(111) and Pt(110) electrodes under hanging meniscus rotating disk electrode (HMRDE) configuration. The comparison between the two different electrolytic media reveals an important influence of the anion in the oxidation kinetics. Once the adsorbed CO layer has been oxidized after the ignition peak, anions are re-adsorbed on the electrode surface and the presence of these anions affects the stationary currents measured at positive potentials. In the negative-going sweep, adsorbed anions are displaced from the surface when the CO oxidation rate is lower than the corresponding CO adsorption rate. The charge associated to this displacement has been measured at high scan rates and is in agreement with that expected from the CO displacement experiments performed at low potentials. Bulk CO oxidation has been studied on platinum stepped surfaces belonging to the series Pt(s)[n(111)×(111)] using the same configuration for low indice Miller electrodes. The general shape of the voltammograms is not significantly affected by the presence of the steps. However, the curves shift towards negative values as the step density increases. Thus, in the positive going scan, a linear relationship is observed for the dependence of the potential for the ignition peak with the step density for surfaces with terraces wider than 5 atoms. In the negative going scan a similar situation is observed for the potential where the current drops to zero. In this case, Pt(111) electrode deviates from the expected behavior, because the formation of the ordered bisulfate adlayer on the electrode. The anion adsorption process is also observed by recordings the voltammograms at high scan rate. All these results have been analyzed in light of the mechanism, discussing the possible effects of the steps and the defects in the CO adlayer. A simple model for the electrocatalytical carbon monoxide bulk oxidation on a platinum electrode was studied by Mean Field Approximation simulation. Under potentiodynamic conditions, the model enabled the investigation of the role of CO adlayer, rate constants and different mass transport conditions on the macroscopic electrochemical response. The results showed that the CO bulk oxidation is a complex process with a delicate balance between the three reaction rates and the displacement of anions by CO adsorption contributes to the overall reaction rate.

Este trabalho teve como objetivo sintetizar eletrólitos híbridos de Nafion-TiO2 e eletrocatalisadores de PtSn/C para a aplicação em células a combustível de oxidação direta de etanol (DEFC) em alta temperatura (130oC). Para tanto, partículas de TiO2 foram incorporadas in-situ em membranas comerciais de Nafion via processo sol-gel. Os materiais resultantes foram caracterizados por análise gravimétrica, absorção de água, DSC, DRX e EDX. Eletrocatalisadores baseados em platina-estanho dispersos em carbono (PtSn/C), de diferentes composições, foram produzidos pelo método de redução por álcool e utilizados como eletrodos anódicos. Os eletrocatalisadores foram caracterizados por DRX, EDX, XPS e MET. A avaliação eletroquímica dos eletrocatalisadores foi realizada por voltametria cíclica, varredura linear anódica de monóxido de carbono (stripping de CO) e cronoamperometria. Ânodos de PtSn/C e cátodos de Pt/C comercial foram dispostos juntamente com os híbridos Nafion-TiO2 para a formação do conjuntos membrana-eletrodos. A avaliação final dos materiais foi realizada por meios de curvas de polarização em células unitárias alimentadas com misturas padrão H2/CO ou etanol no ânodo e com oxigênio no cátodo no intervalo de temperatura de 80 a 130oC. As análises demonstraram que o uso de membranas híbridas diminuiu o crossover de combustível, melhorando o desempenho da célula e que o eletrocatalisador PtSn/C 70:30, produzido pelo método de redução por álcool, foi o que demonstrou melhor desempenho para oxidação de etanol. / In this work, Nafion-TiO2 hybrid electrolytes and PtSn/C electrocatalysts were synthesized for the application in direct ethanol fuel cell operating at high temperature (130oC). For this purpose, TiO2 particles were incorporated in commercial Nafion membranes by an in situ sol gel route. The resulting materials were characterized by gravimetric analysis, water uptake, DSC, XRD and EDX. Electrocatalysts based on carbon dispersed platinum-tin (PtSn/C), with different composition, were produced by alcohol-reduction method and were employed as anodic electrode. The electrocatalysts were characterized by XRD, EDX, XPS and transmission electronic spectroscopy. The electrochemical characterization was conducted by cyclic voltametry, carbon monoxide linear anodic voltammetry (CO stripping), and chronoamperometry. Membrane-electrodes assembly (MEAs) were formed with PtSn/C anodes, Pt/C cathodes and Nafion-TiO2 hybrids. The performance of these MEA was evaluated in single-cell fed with H2/CO mixture or ethanol solution at the anode and oxygen at the cathode in the temperature range of 80-130oC. The analysis showed that the hybrid membranes improved the DEFC performance due to crossover suppression and that PtSn/C 70:30 electrocatalysts, prepared by an alcohol reduction process, showed better performance in ethanol oxidation.

Catalysis has an effect on almost every aspect of our lives. They are used to help grow the food we eat, clean the water we drink and produce the fuels our civilisation is so dependent upon. Homogeneous catalysts, those in the same phase as the reaction medium, are highly selective as a result of their tuneable nature, for example through changes to ligands in a metal complex. However, their separation from the reaction medium can become a problematic, costly, non-green issue, overcome through the use of heterogeneous catalysts which can be removed and recycled by simple separation techniques such as filtering and sedimentation. A major limitation on understanding the behaviour of heterogeneous catalysts is the presence of different active sites due to different exposed crystal surface, concentration of defects and morphological variations. With such considerations, the first section of this thesis focuses on the synthesis of discrete and well-defined nanostructured materials (ceria and titanate) using a single-step hydrothermal method. Nanostructured ceria with different morphologies (particles, rods and cubes), present a high oxygen storage capacity and thermal stability. Their oxidation catalytic activity was assessed using CO oxidation as a model reaction as a function of their physical and chemical properties, tuned by morphological control at the nanoscale. An inverse relationship is observed between crystallite size and rates of reaction normalised per surface area. Smaller crystallites present a constrained geometry resulting in a higher concentration of defects, highly active catalytically due to their unsatisfied coordination and high surface energy. The surface to bulk oxygen ratio generally increased as the surface area increased, however, ceria nanorods present a higher surface oxygen content than that which would be predicted according to their surface area, likely due to the selective exposure of the (110) and (100) dominating crystal surfaces presenting more facile oxygen atoms in their surface. Additionally a relationship between surface to bulk oxygen ratios and activation energies was also ascribed to the more facile nature of oxygen atoms on these surfaces and their more readily formed oxygen vacancies as a result. This activity is as a result of the formation of oxygen vacancies being the rate-controlling step. The thermal stability of nanostructured ceria (particles, rods and cubes) was also studied to investigate their performance under cyclic high temperature applications. For this, the materials were pre-treated at 1000 °C under different atmospheres (inert, oxidative and reducing). In all cases, the materials sinter, consequently resulting in a dramatic decrease in surface area. Interestingly, their catalytic activity per surface area towards CO oxidation, seems to be maintained, although those materials pre-treated under inert and oxidising atmospheres became inactive in consecutive catalytic runs. However, nanostructured ceria pre-treated at 1000 °C under hydrogen appeared to maintain its activity per surface area. The presence of hydrogen during thermal treatment does not only facilitate the removal of surface oxygen, but also the bulk oxygen, resulting in a rearrangement of the structure that facilitates its catalytic stability. Titanate nanotubes were shown to be inactive for CO oxidation and thus were used in the second part of this thesis as a support for platinum nanoparticles to study the effect of the structure and metal-support interaction on the resulting catalytic activity. The study focuses on the effect of different loading methods (ion exchange and incipient wetness impregnation) of platinum nanoparticles on the resulting metal particle size, dispersion, metal-support interaction and consequently their resulting catalytic activity. Ion exchange consistently resulted in smaller nanoparticles with a lower dispersion of sizes and more active catalyst, both in terms of turnover frequency values and activation energy, compared with incipient wetness impregnation. The catalytic activity of the platinum supported on titanate nanotubes increases as the metal particle size decreases to a size value (between 1 and 2.5 nm) below which a dramatic decrease in activity is observed. Despite initial differences in catalytic activity between the different catalysts, it was observed that after initial reactions to 400 °C, the activation energy was independent of metal loading weight and was instead inherent of the loading method, suggesting the presence of similar active sites.

The effect of acoustic and hydrodynamic cavitation on the precipitation of inorganic catalytic materials was investigated. The overall objective was to understand the fundamental factors involved in synthesizing nanometer-size catalytic materials in the 1-10 nm range in a cavitating field. Materials with grain sizes in this range have been associated with enhanced catalytic activity compared to larger grain size materials. A new chemical approach was used to produce titania supported gold by coprecipitation with higher gold yields compared to other synthesis methods. Using this approach, it was determined that acoustic cavitation was unable to influence the gold mean crystallite size compared to non-sonicated catalysts. However, gold concentration on the catalysts was found to be very important for CO oxidation activity. By decreasing the gold concentration from a weight loading of 0.50% down to approximately 0.05%, the rate of reaction per mole of gold was found to increase by a factor of 19. Hydrodynamic cavitation at low pressures (6.9-48 bar) was determined to have no effect on gold crystallite size at a fixed gold content for the same precipitation technique used in the acoustic cavitation studies. By changing the chemistry of the precipitation system, however, it was found that a synergy existed between the dilution of the gold precursor solution, the orifice diameter, and the reducing agent addition rate. Individually, these factors were found to have little effect and only their interaction allowed gold grain size control in the range of 8-80 nm. Further modification of the system chemistry and the use of hydrodynamic cavitation at pressures in excess of 690 bar allowed the systematic control of gold crystallite size in the range of 2-9 nm for catalysts containing (2.27 ± 0.17)% gold. In addition, it was shown that the enhanced mixing due to cavitation led to larger gold yields compared to classical syntheses. The control of gold grain size was gained at the loss of CO activity, which was attributed to the formation of non-removable sodium titanate species. The increased mixing associated with cavitation contributed to the activity loss by partially burying the gold and incorporating more of the sodium titanate species into the catalysts. This work produced the first evidence of hydrodynamic cavitation influencing the gold crystallite size on titania supported gold catalysts and is the only study reporting the control of grain size by simple mechanical adjustment of the experimental parameters. Despite the low activity observed due to sodium titanate, the methodology of adjusting the chemistry of a precipitating system could be used to eliminate such species. The approach of modifying the chemical precipitation kinetics relative to the dynamics of cavitation offers a general scheme for future research on cavitational processing effects.

Organometallic chemistry is a powerful tool for the coupling of simple unsaturated molecules to form complex organic structures. Isonitriles (RNCs) are an attractive alternative to isoelectronic CO as C₁ sources in the pursuit of C,C coupling reactions. The electronic properties of the substituent on nitrogen in RNCs can bring about insertion chemistry that is different from the insertion reactions of CO. The insertion chemistry of RNCs with Group 4 (Ti, Zr, and Hf) butadiene complexes will be described. Cp*(Cl)Ti(2,3-dimethylbutadiene) (2.1) reacts with two equivalents of RNC to give η¹,η²-diimine complexes 2.2 (R = ^tBu) and 2.3 (R = 1-adamantyl). Cp*(Cl)Ti (N,N-di-^tBu-η¹,η²-diimine) (2.2), in the presence of pyridine, fragments to Cp*(Cl)Ti(NtBu)(NC₅H₅) (2.10) and an α-methylene cyclopent-3-enimine 2.11. The hafnium analog of 2.1, Cp*(Cl)Hf(2,3-dimethylbutadiene) (2.14), has been reported to give a cyclic amidine complex when treated with two equivalents of 2,6-dimethylphenyl isonitrile. By X-ray crystallography, however, this work finds that 2.14 and 2,6-dimethylphenyl isonitrile give instead a 2,5-diazahafnacyclopentane that features a σ-interaction between the C¬–C bond of a cyclopropane ring and the Hf. Cp*₂Zr(2,3-dimethylbutadiene) (3.1) reacts with tert-alkyl isonitriles to give η²-iminoacyl complexes Cp*₂⏞(⏟(Zr[CH₂ C(CH₃)C(CH₃)CH₂C)(NR)] 3.2 (R = tBu) and 3.3 (R = 1-adamantyl). Treatment of 3.2 with excess isopropyl isonitrile gives the η¹,η²-bis(iminoacyl) complex Cp*₂⏞(⏟(Zr[C(N^i Pr)CH₂ C(CH₃)C(CH₃)CH₂C)(N)iPr)] (3.4) and free tert-butyl isonitrile. The reaction of 3.1 with 2 equivalents of isopropyl isonitrile also affords 3.4, through the intermediate Cp*₂⏞(⏟(Zr[CH₂ C(CH₃)C(CH₃)CH₂C)(N^iPr)] (3.5). Carbonylation of 3.2 affords the Zr formimidoyl cyclopentadienolate 3.6. Treatment of a Zr hydride cyclopentadienolate (3.7), obtained from the carbonylation of 3.1, with tert-butyl isonitrile also affords 3.6. Isotopic labeling shows that the insertion of tert-butyl isonitrile into 3.1 and 3.7 is reversible.

Neste trabalho foi estudada a reação de metanação do CO em catalisador de Ru/C e sua aplicação em purificação de hidrogênio para utilização em célula a combustível. Tendo como meta a otimização da produção de metano em baixas temperaturas foram preparados materiais de RuxPd(1-x)/C, que também foram tratados termicamente em atmosfera úmida e redutora. Ao final do estudo com CO, também foi investigado o efeito da presença de CO2 no fluxo de hidrogênio, tal qual num sistema real utilizando-se gás de síntese. Os dados obtidos por espectroscopia de energia dispersiva de Raio-X (EDX) mostraram uma boa correspondência entre as composições teóricas e as obtidas experimentalmente dos catalisadores preparados neste trabalho. Analisando-se os difratogramas de Raio-X (DRX) foi possível observar a presença de fases metálicas principalmente de Ru, observando-se também o aumento da cristalinidade do material, promovido pelo tratamento térmico. Além disso, os tamanhos médios de cristalito (TMC) dos materiais foram obtidos com a equação de Scherrer e situaram-se em torno de 2,5 nm. As micrografias de TEM confirmaram o tamanho reduzido das partículas, mas apontaram para uma baixa dispersão dos materiais sobre o suporte, principalmente no caso do Ru/C. Com as medidas de XPS foram identificadas espécies de Ru metálico, Ru(IV), Ru(VII), RuOxHy e Ru.xH2O. O tratamento térmico somente afetou a população de espécies do material Ru/C, que passou a apresentar maior percentual de Ru metálico, em detrimento aos óxidos. Os catalisadores Ru/C e Ru7Pd3/C antes e após o tratamento térmico foram acomodados em filtro de linha gasosa (reator de leito fixo), sendo possível concluir que o tratamento térmico somente promoveu melhora no desempenho metanador para o catalisador Ru/C. Quando utilizados em camada difusora anódica este efeito foi ainda mais pronunciado, sendo observada a produção de CH4 em regime estacionário em Ru/C tratado termicamente quando a temperatura de metanação foi 85 °C. O material mais eficiente foi o de Ru/C após o tratamento térmico, sendo capaz inclusive de hidrogenar seletivamente o CO na presença de CO2. A melhora no desempenho da célula que utilizou este material foi mais notável a 105 °C, possibilitando a operação com 33 mV de sobrepotencial a 1 A.cm-2 quando alimentada com H2 contendo 75 ppm de CO. / In this work the CO methanation reaction over Ru/C catalyst and its practical applications for use as hydrogen purifier for low temperature fuel cell anodes were studied. Aiming at optimizing the low temperature methane production, two main procedures were proposed: The use of RuxPd(1-x)/C materials and its corresponding thermal treatment of the Ru/C catalyst under wet and reductive atmosphere. The effect of the presence of CO2 was then investigated under the same conditions as for CO in order to establish the catalysts selectivity for the CO methanation in the presence of CO2, as in a real system using syngas. EDX data showed a good agreement between the expected compositions and that actually obtained for catalysts prepared in this work. DRX spectra have indicated the presence of metallic phases, particularly of Ru, and the increase of the material crystallinity, promoted by the thermal treatment. Furthermore, the materials mean crystallite sizes were obtained by the use of the Scherer equation and they resulted around 2,5 nm for all samples. TEM micrographs confirmed the small particle size but also showed a poor material dispersion of the metals over the carbon support, especially in the case of Ru/C. XPS measurements have evidenced the presence of ruthenium species such as Ru(IV), Ru(VII), RuOxHy and Ru.xH2O in the prepared ruthenium material. The thermal treatment only affected the Ru species population, showing more metallic ruthenium and less oxides. The Ru/C and Ru7Pd3/C, prior and after the treatment, were accommodated inside a gas filter, and mass spectrometry investigations indicated that the thermal treatment only increased the methanation performance for the Ru/C catalyst. When used in anodic gas diffusion layer, this improvement was even more pronounced, and resulted in stationary methane production even at 85 °C. The most efficient material for CO methanation was Ru/C thermally treated, that promoted the CO methanation in a preferable way even when CO2 was present with percentages as high as 25%. The increase of the electrochemical performance of the fuel cell with this catalyst in the diffusion layer was better when at 105 °C.

Ho Chun Man. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references. / Abstracts in English and Chinese. / ABSTRACT --- p.iv / DECLARATION --- p.vi / ACKNOWLEDGEMENT --- p.vii / TABLE OF CONTENTS --- p.viii / LIST OF TABLES --- p.xi / LIST OF FIGURES --- p.xii / Chapter Chapter One: --- Introduction --- p.1 / Chapter 1.1 --- Overview --- p.1 / Chapter 1.2 --- Fundamental of CeO2 --- p.2 / Chapter 1.3.1 --- Synthesis and Modification of Ceria-based Materials --- p.5 / Chapter 1.3.1 --- Synthetic Method --- p.5 / Chapter 1.3.2 --- "Mesoporous Structure of Ce02, CexZr1-x02" --- p.6 / Chapter 1.3.3 --- Doped Ce02 Materials --- p.6 / Chapter 1.3.4 --- Fabrication of Ceria and Cerium-based Nanoparticles --- p.7 / Chapter 1.4 --- Scope of work --- p.8 / Chapter 1.5 --- References --- p.11 / Chapter Chapter Two: --- Meso- and Macro-porous Pd/CexZr1-x02 as Carbon Monoxide Oxidation Catalysts --- p.16 / Chapter 2.1 --- Introduction --- p.16 / Chapter 2.2 --- Experimental Section --- p.18 / Chapter 2.2.1 --- Sample Preparation - Synthesis of the Catalyst Support --- p.18 / Chapter 2.2.2 --- Addition of Pd to the Catalyst Support --- p.19 / Chapter 2.2.3 --- Characterization --- p.20 / Chapter 2.2.4 --- Carbon monoxide oxidation measurement --- p.21 / Chapter 2.3 --- Results and Discussion --- p.22 / Chapter 2.3.1 --- XRD analysis --- p.22 / Chapter 2.3.2 --- SEM and TEM --- p.25 / Chapter 2.3.3 --- N2-Soprtion --- p.32 / Chapter 2.3.4 --- X-ray Photoelectron Spectroscopy --- p.40 / Chapter 2.3.5 --- Thermal Catalysis Study --- p.45 / Chapter 2.4 --- Conclusion --- p.52 / Chapter 2.5 --- References --- p.54 / Chapter Chapter Three: --- Morphology-Controllable Synthesis of Ce02 Nano and Meso-structures --- p.60 / Chapter 3.1 --- Introduction --- p.60 / Chapter 3.2 --- Experimental Section --- p.62 / Chapter 3.2.1 --- Materials and Experimental Conditions --- p.62 / Chapter 3.2.2 --- Characterization --- p.64 / Chapter 3.3 --- Results and Discussion --- p.67 / Chapter 3.3.1 --- SEM and TEM Analysis --- p.67 / Chapter 3.3.2 --- XRD Analysis --- p.75 / Chapter 3.3.3 --- N2-Soprtion --- p.78 / Chapter 3.3.4 --- X-ray Photoelectron Spectroscopy --- p.84 / Chapter 3.3.5 --- FT-IR Analysis --- p.87 / Chapter 3.3.6 --- GC-MS Analysis --- p.89 / Chapter 3.3.7 --- Proposed Formation of Ce02 nanospheres and their transformation to microrods --- p.95 / Chapter 3.3.8 --- UV absorption spectra and band gap energies --- p.97 / Chapter 3.3.9 --- Thermal Catalysis Study --- p.100 / Chapter 3.4 --- Conclusion --- p.103 / Chapter 3.5 --- References --- p.105 / Chapter Chapter Four: --- Conclusion --- p.110 / LIST OF PUBLICATIONS --- p.112

Chiu, Ka Lok = 多孔生物遺態氧化銅/氧化鈰/氧化鋁之複合物料的製作及其定性分析 / 趙家樂. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references. / Abstract also in Chinese. / Chiu, Ka Lok = Duo kong sheng wu yi tai yang hua tong/yang hua shi/yang hua lu zhi fu he wu liao de zhi zuo ji qi ding xing fen xi / Zhao Jiale. / Abstract --- p.i / 摘要 --- p.iii / Acknowledgment --- p.v / Table of contents --- p.vi / List of table captions --- p.x / List of figure captions --- p.xi / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Carbon monoxide (CO) --- p.1 / Chapter 1.2 --- Production of hydrogen from methanol for fuel cell --- p.2 / Chapter 1.3 --- Catalysts for CO oxidation and methanol reforming --- p.5 / Chapter 1.4 --- Copper-based catalysts --- p.6 / Chapter 1.5 --- Mechanisms in the catalytic processes --- p.7 / Chapter 1.6 --- Synthesis of Cu-based catalysts --- p.10 / Chapter 1.7 --- Potential applications of the biomorphic CuO/CeO2/Al2O3 catalyst --- p.11 / Chapter 1.8 --- Objectives and the thesis layout --- p.12 / Chapter 1.9 --- References --- p.13 / Chapter Chapter 2 --- Methods and Instrumentation --- p.16 / Chapter 2.1 --- Sample preparations --- p.16 / Chapter 2.1.1 --- Syntheses of the biomorphic samples --- p.16 / Chapter 2.1.2 --- Syntheses of the control samples (R1 and R2) --- p.17 / Chapter 2.2 --- Characterization --- p.18 / Chapter 2.2.1 --- Scanning electron microscope (SEM) --- p.18 / Chapter 2.2.2 --- Transmission electron microscopy (TEM) --- p.19 / Chapter 2.2.3 --- X-ray powder diffractometry (XRD) --- p.20 / Chapter 2.2.4 --- Fourier transform infrared (FTIR) spectroscopy --- p.21 / Chapter 2.2.5 --- Raman scattering (RS) spectroscopy --- p.22 / Chapter 2.2.6 --- Differential thermal analysis (DTA) --- p.22 / Chapter 2.2.7 --- Thermogravimetric analysis (TGA) --- p.23 / Chapter 2.2.8 --- Gas sorption surface analysis (GSSA) --- p.24 / Chapter 2.3 --- Catalytic activity --- p.25 / Chapter 2.3.1 --- CO oxidation --- p.25 / Chapter 2.3.2 --- Partial oxidation of methanol (POMe) --- p.27 / Chapter 2.3.3 --- Steam reforming of methanol (SRMe) --- p.28 / Chapter 2.4 --- References --- p.29 / Chapter Chapter 3 --- "Results, discussions and characterization" --- p.31 / Chapter 3.1 --- Biomorphic samples --- p.31 / Chapter 3.1.1 --- Macrostructures --- p.31 / Chapter 3.1.2 --- SEM and TEM results --- p.32 / Chapter 3.1.3 --- XRD analysis and chemical compositions --- p.35 / Chapter 3.1.4 --- RS results --- p.41 / Chapter 3.1.5 --- FTIR results --- p.44 / Chapter 3.1.6 --- Thermal property --- p.46 / Chapter 3.1.7 --- Porosity analysis --- p.48 / Chapter 3.2 --- Control sample R1 --- p.52 / Chapter 3.2.1 --- Microstructures --- p.52 / Chapter 3.2.2 --- Surface area and porosity --- p.55 / Chapter 3.2.3 --- Thermal property --- p.56 / Chapter 3.2.4 --- "XRD, FTIR and RS results" --- p.58 / Chapter 3.3 --- Control sample R2 --- p.60 / Chapter 3.3.1 --- Microstructures --- p.60 / Chapter 3.3.2 --- Surface area and porosity --- p.61 / Chapter 3.3.3 --- "XRD, FTIR and RS results" --- p.62 / Chapter 3.3.4 --- Thermal property --- p.63 / Chapter 3.4 --- Formation mechanisms of the biomorphic samples --- p.64 / Chapter 3.5 --- Impacts of the Cu/Ce/Al ratios on the CuO dispersion --- p.66 / Chapter 3.6 --- Cotton biotemplate --- p.66 / Chapter 3.7 --- Formation mechanisms of R1 and R2 --- p.67 / Chapter 3.8 --- References --- p.69 / Chapter Chapter 4 --- Evaluations of Catalytic Activities --- p.71 / Chapter 4.1 --- CO oxidation --- p.71 / Chapter 4.2 --- POMe --- p.79 / Chapter 4.3 --- SRMe --- p.91 / Chapter 4.4 --- Physical properties of the biomorphic samples before and after the reactions --- p.97 / Chapter 4.5 --- Structure of the sample and its catalytic performance --- p.102 / Chapter 4.6 --- CuO dispersion and the catalytic performance --- p.103 / Chapter 4.7 --- Al2O3 and CeO2 and the catalytic performance --- p.105 / Chapter 4.8 --- Catalytic performance of the biomorphic samples and R2 --- p.108 / Chapter 4.9 --- References --- p.109 / Chapter Chapter 5 --- Conclusions and suggestions for further studies --- p.110 / Chapter 5.1 --- Conclusions --- p.110 / Chapter 5.2 --- Future works --- p.112 / Chapter 5.3 --- References --- p.114