Yes / The present study explored a novel oxidative desulfurization (ODS) method of light gas oil fuel, which combines a catalytic oxidation step of the dibenzothiophene compound directly in the presence of molecular air as oxidant to obtain high quality fuel for light gas oil. In chemical industries and industrial research, catalysis play a significant role. Heightened concerns for cleaner air together with stricter environmental legislations on sulphur content in addition to fulfill economic have created a driving force for the improvement of more efficient technologies and motivating an intensive research on new oxidative catalysts. As the lower quality fuel becomes more abundant, additional challenges arise such as more severe operation conditions leading to higher corrosion of the refinery installations, catalyst deactivation and poisoning. Therefore, among the technologies to face these challenges is to develop catalysts that can be applied economically under moderate conditions. The objective of this work is to design a suitable synthetic catalyst for oxidative desulfurization (ODS) of light gas oil (LGO) containing model sulphur compound (dibenzothiophene (DBT)) using air as oxidant and operating under different but moderate operating conditions. The impregnation method is used to characterize two homemade catalysts, cobalt oxide (Co3O4/γ-Al2O3) and manganese oxide (MnO2/γ-Al2O3). The prepared catalysts showed that the manganese oxide has a good impregnation (MnO2=13%), good pore size distribution and larger surface area. A set of experiments related to ODS of dibenzothiophene has been carried out in a continuous flow isothermal trickle bed reactor using light gas oil as a feedstock utilizing both catalysts prepared in-house. At constant pressure of 2 bar and with different initial concentration of sulphur within dibenzothiophene, the temperature of the process was varied from 403K to 473K and the liquid hourly space velocity from(LHSV) was varied from 1 to 3 hr-1. The results showed that an increase in reaction temperature and decreasing in LHSV, higher conversion was obtained. Although both catalysts showed excellent catalytic performance on the removal of molecule sulphur compound from light gas oil, the catalyst MnO2 catalyst exhibited higher conversion than Co3O4 catalyst at the same process operating conditions.

No description available.

Ce travail vise l'étude de l'oxydation catalytique des Composés Organiques Volatils (COVs). L'objectif principal est de trouver des matériaux catalytiques qui sont des alternatives aux métaux nobles très onéreux. La recherche des matériaux catalytiques actifs, sélectifs, stables dans le temps et à base de métaux de transition est abordée. Afin d'améliorer les performances catalytiques des métaux de transition, la dispersion de l'espèce métallique doit être optimisée en utilisant une méthode de synthèse adéquate. Les différents solides préparés ont été caractérisés par différentes techniques physico-chimiques : la Diffraction des Rayons X (DRX), les Analyses Thermiques (ATD/ATG), la Spectroscopie Infrarouge (IR), la Réduction en Température Programmée (H₂-RTP), la Microscopie Electronique à Balayage (MEB), la Spectroscopie de Photoélectrons induits par rayons X (SPX)...De plus, les oxydes obtenus ont été testés dans les réactions d'oxydation totale du COV propène. En premier lieu, nous avons focalisé notre travail sur la préparation d'une série d'oxydes mixtes Co-Mg/Al-Fe par voie hydrotalcite afin d'obtenir des propriétés intéressantes en catalyse hétérogène. Cette étude consiste surtout à évaluer la substitution des cations bivalents et trivalents. Il s'est avéré que le solide contenant à la fois du cobalt et du fer (CoFe) possède l'activité catalytique la plus élevée. L'intérêt de la voie hydrotalcite par rapport à d'autres méthodes de synthèse, telles que la méthode classique et le mélange mécanique des oxydes a été mis en évidence. En second lieu, l'utilisation des irradiations micro-ondes lors de la synthèse des matériaux hydrotalcites a été également étudiée comme une méthode de synthèse non-conventionnelle. Un effet bénéfique a été observé avec l'utilisation des micro-ondes dû principalement à des surfaces spécifiques plus élevées et à une meilleure réductibilité des espèces oxydes. En outre, cette étude vise également la mise au point de cette nouvelle méthode. De ce fait, l'optimisation de la température, durée et puissance des irradiations micro-ondes a été effectuée sur le solide CoFe, afin de montrer l'influence de chaque paramètre sur les propriétés physico-chimiques des matériaux. En troisième lieu, la synthèse d'une série de catalyseurs par voie hydrotalcite avec différentes teneurs en Co²⁺ et Fe³⁺ a été effectuée. L'influence du rapport molaire sur la structure hydrotalcite a été montrée. Une comparaison entre ces solides et ceux préparés par la méthode micro-ondes a été également abordée. / This work aims to study the catalytic oxidation of Volatile Organic Compounds (VOCs). The main objective is to find catalytic materials that are alternatives to very expensive noble metals. The search for transition metal based catalysts is investigated. Furthermore, to improve the catalytic performance of the transition metals, their dispersion must be optimized using an adequate synthetic method. The various prepared solids were characterized by different physicochemical techniques : X-ray Diffraction (XRD), Thermal Analysis (TDA/TGA), Infrared Spectroscopy (IR), Temperature Programmed Reduction by hydrogen (H₂-TPR), Scanning Electron Microscopy (SEM), X-ray Photoelectron Spectroscopy (XPS)...Moreover, the obtained oxides were tested in the total oxidation of the VOC propene. Firstly, we focused our work on the preparation of a series of Co/Fe hydrotalcites -like samples by the traditional co-precipitation method. This study consists mainly of evaluating the substitution of bivalent and trivalent cations. It has been found that the solid containing both cobalt and iron (CoFe) has the highest catalytic activity. The interest of the hydrotalcite route compared to other methods of synthesis, such as the classical method and the mechanical mixing of oxides was put into evidence. Secondly, the use of microwave irradiation during the synthesis of hydrotalcite materials has also been studied as an unconventional method of synthesis. A beneficial effect has been observed with the use of microwaves due mainly to higher specific surface areas and better reducibility of the oxide species. In addition, an optimization of the temperature, duration, and power of the microwave irradiations was carried out on the CoFe solid, in order to show the influence of each parameter on the physico-chemical properties of the materials. Thirdly, the synthesis of a series of hydrotalcite catalysts with different ratio of Co²⁺ and Fe³⁺ was carried out. The influence of the molar ratio on the hydrotalcite structure has been shown. A comparison between these solids and those prepared by the microwave method was also discussed.

Energijos kaupiklių kūrimas pastaraisiais metais tapo svarbia mokslo aktualija. Elektrocheminiai kondensatoriai pasižymi didesne galia, ilgesniu savaiminio išsikrovimo laiku ir didesniu darbo ciklų skaičiumi negu tradicinės elektrocheminės baterijos. Didžiausia savitąja talpa pasižymi RuO2, tačiau jo praktinį taikymą riboja didelė kaina, todėl ieškoma pigesnių pakaitalų. Pastaraisiais metais aktyviai tiriamas kobalto oksidas. Svarbu yra surasti ekonomiškai efektyvius ir paprastus metodus, leidžiančius padidinti kobalto oksidų pseudotalpas. Darbe nustatytos elektrocheminio Co nusodinimo sąlygos, kurioms esant yra formuojama pluoštinė nanostruktūra, pasižyminti dideliu paviršiaus plotu. Anodinės poliarizacijos būdu buvo suformuoti kobalto hidro/oksido sluoksniai ir ištirta jų pseudotalpa ant skirtingų substratų: nanostruktūrinės, magnetroninės-plazminės dangos ir metalurginio Co. Pseudotalpinė kobalto hidro/oksidų elgsena buvo ištirta ciklinės voltamperometrijos metodu kartu su elektrocheminėmis kvarco kristalo svarstyklėmis (EKKM). Oksidiniai sluoksniai parodė grįžtamą redukcijos-reoksidacijos ir atitinkamą pseudotalpinę elgseną. Per kelis tūkstančius anodinių ciklų buvo parodyta, kad oksidinis sluoksnis išliko stabilus. Nustatyta, kad hidro/oksidų, suformuotų ant nanostruktūrinės Co dangos, talpa maždaug 5 kartus didesnė nei suformuotų ant metalurginio Co. Šiame darbe pasiūlytas naujas kobalto oksido formavimo būdas: sulfidinės Co(OH)2–CoS kompozicijos formavimas ir... [toliau žr. visą tekstą] / Design of high efficiency energy accumulators has recently become an important issue of science and technology. Electrochemical capacitors are distinguished for a greater power, a longer self-discharge time and a greater number of work cycles as compared to those of traditional electrochemical batteries. Effective supercapacitors are mainly produced of RuO2, which is distinguished from other metals for its nearly highest specific capacity, however its practical application is limited by its high price, therefore efforts are under way to find cheaper substitutes. Recently cobalt oxide has been intensively studied. It is important to find economically effective and simple methods which will make it possible to increase the pseudocapacities of cobalt oxides. The conditions of electrochemical cobalt deposition, under which the fiber Co nanostructure possessing a great surface area is formed, have been determined in the work. Cobalt hydro/oxide layers were formed by the anodic polarization method and their pseudocapacity was studied on various substrates: nanostructured, magnetron-sputtered coating and metallurgical cobalt. The pseudocapacitor behaviour of cobalt hydro/oxides was studied by using the cyclic voltammetry method along with electrochemical quartz crystal mocrobalance (EKKM). Oxide layers showed oxidation-reduction and corresponding pseudo-capacitor behaviour.It has been shown that the oxide layer is stable and it withstands a few thousand polarization cycles. It has... [to full text]

Design of high efficiency energy accumulators has recently become an important issue of science and technology. Electrochemical capacitors are distinguished for a greater power, a longer self-discharge time and a greater number of work cycles as compared to those of traditional electrochemical batteries. Effective supercapacitors are mainly produced of RuO2, which is distinguished from other metals for its nearly highest specific capacity, however its practical application is limited by its high price, therefore efforts are under way to find cheaper substitutes. Recently cobalt oxide has been intensively studied. It is important to find economically effective and simple methods which will make it possible to increase the pseudocapacities of cobalt oxides. The conditions of electrochemical cobalt deposition, under which the fiber Co nanostructure possessing a great surface area is formed, have been determined in the work. Cobalt hydro/oxide layers were formed by the anodic polarization method and their pseudocapacity was studied on various substrates: nanostructured, magnetron-sputtered coating and metallurgical cobalt. The pseudocapacitor behaviour of cobalt hydro/oxides was studied by using the cyclic voltammetry method along with electrochemical quartz crystal mocrobalance (EKKM). Oxide layers showed oxidation-reduction and corresponding pseudo-capacitor behaviour.It has been shown that the oxide layer is stable and it withstands a few thousand polarization cycles. It has... [to full text] / Energijos kaupiklių kūrimas pastaraisiais metais tapo svarbia mokslo aktualija. Elektrocheminiai kondensatoriai pasižymi didesne galia, ilgesniu savaiminio išsikrovimo laiku ir didesniu darbo ciklų skaičiumi negu tradicinės elektrocheminės baterijos. Didžiausia savitąja talpa pasižymi RuO2, tačiau jo praktinį taikymą riboja didelė kaina, todėl ieškoma pigesnių pakaitalų. Pastaraisiais metais aktyviai tiriamas kobalto oksidas. Svarbu yra surasti ekonomiškai efektyvius ir paprastus metodus, leidžiančius padidinti kobalto oksidų pseudotalpas. Darbe nustatytos elektrocheminio Co nusodinimo sąlygos, kurioms esant yra formuojama pluoštinė nanostruktūra, pasižyminti dideliu paviršiaus plotu. Anodinės poliarizacijos būdu buvo suformuoti kobalto hidro/oksido sluoksniai ir ištirta jų pseudotalpa ant skirtingų substratų: nanostruktūrinės, magnetroninės-plazminės dangos ir metalurginio Co. Pseudotalpinė kobalto hidro/oksidų elgsena buvo ištirta ciklinės voltamperometrijos metodu kartu su elektrocheminėmis kvarco kristalo svarstyklėmis (EKKM). Oksidiniai sluoksniai parodė grįžtamą redukcijos-reoksidacijos ir atitinkamą pseudotalpinę elgseną. Per kelis tūkstančius anodinių ciklų buvo parodyta, kad oksidinis sluoksnis išliko stabilus. Nustatyta, kad hidro/oksidų, suformuotų ant nanostruktūrinės Co dangos, talpa maždaug 5 kartus didesnė nei suformuotų ant metalurginio Co. Šiame darbe pasiūlytas naujas kobalto oksido formavimo būdas: sulfidinės Co(OH)2–CoS kompozicijos formavimas ir... [toliau žr. visą tekstą]

Made available in DSpace on 2014-07-29T15:12:44Z (GMT). No. of bitstreams: 1 Dissertacao Gustavo Amorim Santos.pdf: 699656 bytes, checksum: 971524b5001f034de32cefb99d226301 (MD5) Previous issue date: 2010-08-31 / In this work, a methodology for the synthesis of silica-cobalt oxide-based composites was developed by modifying the well known Stöber sol-gel method. The main novelty of the procedure was the use of colloidal suspensions of cobalt oxide or cobalt hydroxide nanoparticles (Co3O4,Co(OH)2), which were previously prepared from the precipitation of Co2+ ions in alkaline medium. The silica-cobalt composites having cobalt contents (w/w) around 8.4 to 11% were characterized by X-ray diffraction (XRD), infrared spectroscopy (FTIR), thermogravimetric and differential thermal analysis (TG/DTA), temperature programmed reduction (TPR) and adsorption /desorption of nitrogen. The characteristics of the composites which were prepared by employing the colloidal suspensions were compared to those exhibited by other composites which were obtained from cobalt nitrate solution. The influence of cerium nitrate and citric acid was also evaluated. The methodology employed in the synthesis of nanoparticles and composites were reproducible and the prepared materials showed surface areas (300 to 567 cm3/g) and pore diameters (3.8 to 8.1 nm) values which were considered appropriate to use them as catalysts. The calcined composites which were prepared using colloidal suspensions of Co3O4 nanoparticles showed TPR curves with maximum picks at relatively low temperatures, in the range of 275 to 520 oC, suggesting the existence of weak silica-cobalt interactions. The average diameter of Co3O4 crystallites varied from 22 to 30 nm. However, the use of citric acid as a pore-forming agent in the sol-gel synthesis led to composites with enhanced silica-cobalt interactions as a result of the dissolution of the cobalt oxide particles and formation of cobalt silicate. The incorporation of cerium nitrate in the sol-gel mixture did not modify the textural properties of the composites but the reduction of cobalt oxide to metallic cobalt was retarded. The composite which was obtained from the cobalt hydroxide, β-Co(OH)2, colloidal suspension showed weak silica-cobalt interactions as well as intermediate ones, the average diameter of Co3O4 crystallites being 12 nm. Differently from the composites obtained from colloidal suspensions, those which were synthesized using a cobalt nitrate aqueous solution presented mainly cobalt silicate and a low quantity of Co3O4 particles of 11 and 17 nm. The TPR curves of these composites indicated very strong silica-cobalt interactions, as expected. The composites were evaluated as catalysts in the reduction reaction of NO to N2 with the oxidation of CO to CO2. The composites which were prepared from Co3O4 colloidal suspensions without the use of citric acid as pore-forming agent showed maximum conversions as high as 90% for both NO to N2 and CO to CO2, at temperatures above 600°C. On the other hand, the composite prepared using critic acid showed much lower conversions (60 %) at the same temperature. / Neste trabalho foi desenvolvida uma metodologia de síntese de compósitos de óxido de cobalto e sílica a partir de adaptações no método sol-gel do tipo Stöber. A principal novidade do procedimento consistiu na utilização de suspensões coloidais de nanopartículas de óxido ou hidróxido de cobalto (Co3O4, Co(OH)2), as quais foram previamente preparadas por precipitação de íons Co2+ em meio alcalino. Os compósitos de sílica-cobalto contendo teores de cobalto entre 8,4 e 11% (m/m) foram caracterizados por espectroscopia de absorção atômica (AA), difratometria de raios-X (DRX), espectroscopia na região do infravermelho médio com transformada de Fourier (FTIR), análise termogravimétria e térmica diferencial (TG/DTA), redução a temperatura programada (TPR) e adsorção/dessorção de nitrogênio. As características dos compósitos preparados empregando-se suspensões de nanopartículas foram comparadas com as de outros compósitos obtidos a partir de solução de nitrato de cobalto, sendo também avaliada a influência da adição de nitrato de cério e de ácido cítrico. A metodologia desenvolvida mostrou-se reprodutível e os materiais obtidos apresentaram valores adequados de área superficial (300 a 567 cm3/g) e diâmetro de poros (3,8 a 8,1 nm) para serem utilizados como catalisadores. Os compósitos preparados utilizando-se suspensões coloidais de nanopartículas de Co3O4 apresentaram, após calcinação, curvas de redução termoprogramada cujos picos máximos ocorreram em temperaturas relativamente baixas, na faixa de 275 a 520 oC, sugerindo a existência de interações fracas entre a sílica e o cobalto. O diâmetro médio dos cristalitos de Co3O4 nesses compósitos variou entre 22 e 30 nm. No entanto, a utilização de ácido cítrico como agente formador de porosidade na síntese desses compósitos provocou o aumento da interação sílica-cobalto, como resultado da dissolução das partículas de óxido de cobalto e formação de silicato de cobalto. A utilização de nitrato de cério nas sínteses não alterou as propriedades texturais dos compósitos, mas, como esperado, dificultou a redução do óxido de cobalto para cobalto metálico. O compósito obtido a partir de suspensão coloidal de hidróxido de cobalto, -Co(OH)2, por sua vez, apresentou tanto interações sílica-cobalto fracas como intermediárias, sendo de 12 nm o diâmetro médio dos cristalitos de Co3O4, após calcinação do material. Diferentemente dos compósitos preparados a partir das suspensões coloidais do óxido de cobalto, os compósitos que foram sintetizados utilizando-se solução de nitrato de cobalto mostraram, após calcinação, a presença silicato de cobalto e pequena quantidade de partículas de Co3O4 de diâmetros entre 11 e 17 nm. As curvas de TPR desses compósitos indicaram, como esperado, interações sílica-cobalto fortes. Os compósitos foram avaliados na reação de redução do NO em N2 com oxidação do CO a CO2. Para os compósitos em que foram utilizadas nanopartículas de Co3O4 previamente preparadas, na ausência de ácido cítrico, houve conversões máximas de até 90% do NO em N2 e do CO em CO2.. Isso ocorreu em temperaturas superiores a 600 °C. Por outro lado, a utilização do ácido cítrico concomitantemente à incorporação das nanopartículas de Co3O4, conduziu a taxas de conversões inferiores a 60%, em temperaturas superiores a 600 °C.

Submitted by Luanna Matias (lua_matias@yahoo.com.br) on 2015-03-05T14:07:37Z No. of bitstreams: 2 Dissertação - Alécia Maria Golçalves - 2011.pdf: 3110848 bytes, checksum: 0b6c29c9a2a058e2fd9e9c31230c02a6 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luanna Matias (lua_matias@yahoo.com.br) on 2015-03-05T16:24:15Z (GMT) No. of bitstreams: 2 Dissertação - Alécia Maria Golçalves - 2011.pdf: 3110848 bytes, checksum: 0b6c29c9a2a058e2fd9e9c31230c02a6 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2015-03-05T16:24:15Z (GMT). No. of bitstreams: 2 Dissertação - Alécia Maria Golçalves - 2011.pdf: 3110848 bytes, checksum: 0b6c29c9a2a058e2fd9e9c31230c02a6 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2011-09-12 / The reaction of steam reforming of ethanol is a way produce hydrogen gas, but it is essential to use catalysts to facilitate this reaction. This paper proposes the preparation of nanostructured catalysts impregnated with titanium oxide nanoparticles of cobalt and/or magnesium oxide. From the results of XRD, TEM and BET titanium oxide (anatase - T) obtained from the sol-gel method showed particles with crystallite size of 5-8 nm and a specific surface area of 258 m2g-1. The sodium titanate nanotubes were synthesized by alkaline hydrothermal treatment of titanium oxide in anatase phase, commercial (NT) and synthesized (NTS), resulting in nanotubes with outer diameter from 10 to 30 nm and length of 45 to 110 nm. The impregnation process of the oxides of cobalt and/or magnesium did not cause structural changes in the supports, and present level of metal below the desired level. Profiles of temperature programmed reduction showed the presence of cobalt oxide in the impregnated catalysts. The catalysts evaluated in the reaction of reforming ethanol (Co3O4, NT, NTCo, NTMgCo, and NTMgCo700 NTSMgCo) had ethanol conversion close to 100%, and the catalysts NTSMgCo, NTMgCo700 showed higher selectivity to 87.8% and 89,2%, respectively. With the exception of NT and NTCo catalysts showed no formation of ethylene. The amount of carbon after the catalytic tests ranged from 3.4 to 12.9 (%m/m/h). / A reação de reforma a vapor do etanol é uma forma de produzir o gás hidrogênio, porém é imprescindível a utilização de catalisadores para viabilizar esta reação. Este trabalho propõe catalisadores nanoestruturados de titânio impregnado com nanopartículas de óxido de cobalto e/ou óxido de magnésio. A partir dos resultados de DRX e MET e BET o TiO2 - anatásio obtido a partir do método sol-gel apresentou nanopartículas com tamanho de cristalitos de 5 - 8nm e uma área superficial específica de 258m2g-1. Os nanotubos de titanatos de sódio foram sintetizados por tratamento hidrotérmico alcalino de óxidos de titânio - anatásio com tamanhos de partículas diferentes, apresentaram diâmetro externo de 10 - 30nm e comprimento de 45 - 110 nm. As curvas termogravimétricas mostraram que a decomposição térmica está relacionada à eliminação de água. O processo de impregnação dos diferentes óxidos de cobalto e/ou magnésio apresentou teores menores que o desejado e não proveram alterações estruturais nos nanotubos. O RTP do Co3O4 apresentou três bandas de redução, com máximos em 445, 550 e 660 °C e estas bandas também foram identificadas nos catalisadores impregnados com Co3O4. Os catalisadores Co, NT, NTCo, NTMgCo, NTMgCo700 e NTSMgCo apresentaram conversão do etanol próximo a 100%, sendo que os catalisadores NTSMgCo, NTMgCo700 apresentaram maior seletividade a H2 87,8% e 89,2%, respectivamente, e NTMgCo apresentou seletividade a H2 81,4 % e não formou acetaldeído. Após os testes catalíticos foram observados a deposição de carbono, variando 10 – 53%.

>Magister Scientiae - MSc / To address the urgent need for safe potable water in South Africa’s rural areas, sustainable systems for water disinfection at the village-scale of operation are required.In this thesis, the development of a small-scale water chlorination system that runs on salt and solar panels is described. The system combines a membrane-based hypochlorite generator, or “membrane electrolyser”, with an automated hypochlorite dosing system.The system was designed to (i) coordinate hypochlorite production and dosing automatically in a flow-through system, and (ii) fit inline with low pressure pipelines from overhead storage tanks or raised water sources. Low cost materials were used for construction, and water-powered mechanisms were devised to control both brine supply to the electrolyser and regulation of water flow. The capacity of the system was based on the maximum daily output of the electrolyser at ~20 g of sodium hypochlorite. This was sufficient chlorinate up to 10 kL of water per day using less than 80 g of salt and less than 0.1 kW.h of electricity. The cost of the system was estimated at ~R10 000 and therefore potentially affordable for communities up to 100 people, e.g. small farms and villages.Testing of the system was carried out at a farm site in Worcester (Western Cape) using remote monitoring of current levels in the electrolyser. Operation of the system over a two month test period, dosing at ~4 mg/L, produced consistent chlorination measured as(FAC). Community participation in maintenance of the brine supply was managed and chlorinated water was made available to the community after a brief social survey was conducted. Community awareness of chlorination was minimal. No significant history of diarrhoea was reported. However, the community regularly boiled their tap water in response to turbidity increase in summer.The system was affected by turbidity increase in the local water, which caused a drop in electrolyser current and chlorine production due to particle blockage of the membrane in the electrolyser. However, turbidity at acceptable levels for chlorination was found to have no detrimental effect on the system’s performance. The system showed promise for rural implementation providing low turbidity was maintained. Therefore,groundwater sites, and surface waters with appropriate clarification systems are recommended for the system’s installation. Further testing of the system will be required to establish its long term viability in the hands of a rural community.

<p>Proton exchange membrane fuel cells and lithium polymer batteries are important as future power sources in electronic devices, vehicles and stationary applications. The development of these power sources involves finding and characterising materials that are well suited r the application.</p><p>The materials investigated in this thesis are the perfluorosulphonic ionomer Nafion^TM(DuPont) and metal oxides incorporated into the membrane form of this material. The ionomer is used as polymer electrolyte in proton exchange membrane fuel cells (PEMFC) and the metal oxides are used as cathode materials in lithium polymer batters (LPB).</p><p>Crystallinity in cast Nafion films can be introduced by ion beam exposure or aging. Spectroscopic investigations of the crystallinity of the ionomer indicate that the crystalline regions contain less water than amorphous regions and this could in part explain the drying out of the polymer electrolyte membrane in a PEMFC.</p><p>Spectroscopic results on the equilibrated water uptake and the state of water in thin cast ionomer films indicate that there is a full proton transfer from the sulphonic acid group in the ionomer when there is one water molecule per sulphonate group.</p><p>The LPB cathode materials, lithium manganese oxide and lithium cobalt oxide, were incorporated <i>in situ</i> in Nafion membranes. Other manganese oxides and cobalt oxides were incorporated <i>in situ</i> inside the membrane. Ion-exchange experiments from HcoO₂to LiCoO₂within the membrane were also successful.</p><p>Fourier transform infrared spectroscopy, Raman spectroscopy and X-ray diffraction were used for the characterisation of the incorporated species and the Nafion film/membrane.</p>

Proton exchange membrane fuel cells and lithium polymer batteries are important as future power sources in electronic devices, vehicles and stationary applications. The development of these power sources involves finding and characterising materials that are well suited r the application. The materials investigated in this thesis are the perfluorosulphonic ionomer NafionTM (DuPont) and metal oxides incorporated into the membrane form of this material. The ionomer is used as polymer electrolyte in proton exchange membrane fuel cells (PEMFC) and the metal oxides are used as cathode materials in lithium polymer batters (LPB). Crystallinity in cast Nafion films can be introduced by ion beam exposure or aging. Spectroscopic investigations of the crystallinity of the ionomer indicate that the crystalline regions contain less water than amorphous regions and this could in part explain the drying out of the polymer electrolyte membrane in a PEMFC. Spectroscopic results on the equilibrated water uptake and the state of water in thin cast ionomer films indicate that there is a full proton transfer from the sulphonic acid group in the ionomer when there is one water molecule per sulphonate group. The LPB cathode materials, lithium manganese oxide and lithium cobalt oxide, were incorporated in situ in Nafion membranes. Other manganese oxides and cobalt oxides were incorporated in situ inside the membrane. Ion-exchange experiments from HcoO2 to LiCoO2 within the membrane were also successful. Fourier transform infrared spectroscopy, Raman spectroscopy and X-ray diffraction were used for the characterisation of the incorporated species and the Nafion film/membrane.