In this study SBA-15 mesoporous silica template was synthesized and used as a sacrificial template in the preparation of ordered mesoporous carbon material. A chemical vapour deposition (CVD) technique using LPG or alternatively sucrose, pyrolyzed upon a mesoporous Si matrix were used to produce nanostructured ordered mesoporous carbon (OMC) with graphitic character after removing the Si template. The sucrose method was found to be a suitable route for preparing OMC. The OMC was used as a conductive three dimensional porous support for depositing catalytic nanophase Pt metal. Deposition of Pt nanoparticles on OMC was accomplished using a CVD method with Pt(acac)2 as a precursor. The synthesized nano-composite materials were characterized by several techniques such as, HRTEM, HRSEM, EDS, XRD, BET, TGA, FT-IR and CV.

In this study SBA-15 mesoporous silica template was synthesized and used as a sacrificial template in the preparation of ordered mesoporous carbon material. A chemical vapour deposition (CVD) technique using LPG or alternatively sucrose, pyrolyzed upon a mesoporous Si matrix were used to produce nanostructured ordered mesoporous carbon (OMC) with graphitic character after removing the Si template. The sucrose method was found to be a suitable route for preparing OMC. The OMC was used as a conductive three dimensional porous support for depositing catalytic nanophase Pt metal. Deposition of Pt nanoparticles on OMC was accomplished using a CVD method with Pt(acac)2 as a precursor. The synthesized nano-composite materials were characterized by several techniques such as, HRTEM, HRSEM, EDS, XRD, BET, TGA, FT-IR and CV.

Magister Scientiae - MSc / In this study SBA-15 mesoporous silica template was synthesized and used as a sacrificial template in the preparation of ordered mesoporous carbon material. A chemical vapour deposition (CVD) technique using LPG or alternatively sucrose, pyrolyzed upon a mesoporous Si matrix were used to produce nanostructured ordered mesoporous carbon (OMC) with graphitic character after removing the Si template. The sucrose method was found to be a suitable route for preparing OMC. The OMC was used as a conductive three dimensional porous support for depositing catalytic nanophase Pt metal. Deposition of Pt nanoparticles on OMC was accomplished using a CVD method with Pt(acac)2 as a precursor. The synthesized nano-composite materials were characterized by several techniques such as, HRTEM, HRSEM, EDS, XRD, BET, TGA, FT-IR and CV. / South Africa

<p>In this study novel composite electrodes were developed, in which the catalytic components were deposited in nanoparticulate form. The efficiency of the nanophase catalysts and membrane electrodes were tested in an important electrocatalytic process, namely hydrogen production by water electrolysis, for renewable energy systems. The activity of electrocatalytic nanostructured electrodes for hydrogen production by water electrolysis were compared with that of more conventional electrodes. Development of the methodology of preparing nanophase materials in a rapid, efficient and simple manner was investigated for potential application at industrial scale. Comparisons with industry standards were performed and electrodes with incorporated nanophases were characterized and evaluated for activity and durability.</p>

<p>In this study novel composite electrodes were developed, in which the catalytic components were deposited in nanoparticulate form. The efficiency of the nanophase catalysts and membrane electrodes were tested in an important electrocatalytic process, namely hydrogen production by water electrolysis, for renewable energy systems. The activity of electrocatalytic nanostructured electrodes for hydrogen production by water electrolysis were compared with that of more conventional electrodes. Development of the methodology of preparing nanophase materials in a rapid, efficient and simple manner was investigated for potential application at industrial scale. Comparisons with industry standards were performed and electrodes with incorporated nanophases were characterized and evaluated for activity and durability.</p>

Doctor Scientiae - DSc / In this study novel composite electrodes were developed, in which the catalytic components were deposited in nanoparticulate form. The efficiency of the nanophase catalysts and membrane electrodes were tested in an important electrocatalytic process, namely hydrogen production by water electrolysis, for renewable energy systems. The activity of electrocatalytic nanostructured electrodes for hydrogen production by water electrolysis were compared with that of more conventional electrodes. Development of the methodology of preparing nanophase materials in a rapid, efficient and simple manner was investigated for potential application at industrial scale. Comparisons with industry standards were performed and electrodes with incorporated nanophases were characterized and evaluated for activity and durability. / South Africa

[pt] A preocupação ambiental é um tema que vem ganhando seu espaço em pesquisas de diversas áreas, é necessário que a dependência da utilização de combustíveis fósseis não aumente, para que os impactos gerados por eles no meio ambiente como a poluição e o efeito estufa sejam então controlados. Além disso, o uso de fontes alternativas como matéria-prima para a geração de energia possui grande importância nessa substituição. O presente trabalho visa avaliar o potencial do óleo de coco para a produção de um bio-óleo a partir da catálise heterogênea utilizando catalisadores metálicos de Ni e Mo suportados em sílica mesoporosa (SBA-15). Os catalisadores e o suporte foram sintetizados manualmente, calcinados e passaram por diversas análises de caracterização. Para a reação, utilizou-se a temperatura de 370 graus Celsius, pressão na faixa de 10 a 15 bar, e um tempo de reação de 2 horas. Após o bio-óleo ser produzido o mesmo foi filtrado e destilado, para se trabalhar na faixa do diesel. Por fim, o óleo passou por duas análises de caracterização, sendo elas, a determinação do ponto de fulgor e massa específica, para então avaliar o potencial do óleo de coco na substituição dos combustíveis tradicionais. A síntese do suporte e a impregnação dos catalisadores foi considerada satisfatória, pois os resultados se apresentaram de acordo com a literatura, mostrando que se tratam de materiais mesoporosos, e além disso, a presença dos metais foi comprovada. Após as análises de caracterização, o bio-óleo produzido a partir do catalisador de níquel foi considerado o melhor, visto que, suas propriedades ficaram dentro da faixa esperada (ponto de fulgor de 41 graus Celsius e uma massa específica de 0,8408 g/cm3) para um combustível derivado do petróleo, e além disso, teve uma eficiência de 45,05 porcento na redução da concentração de oxigênio. / [en] The environmental concern is a theme that has been gaining its place in several research, so it is necessary that the dependence on using fossil fuels must not increase, to control the impacts, like the pollution and the greenhouse effect, with are generate by them. Furthermore, the use of alternatives sources like feedstock to generation of energy has a big importance in this replacement. This work wants to evaluate the coconut oil s potential to produce a bio oil by heterogeneous catalysis using three metals catalysts (nickel, molybdenum and both of them) supported in a mesoporous silica. The catalysts and the support were manually synthesized, calcined and characterized. For the reaction, we used 370 Celsius degrees, a pressure in the range 10-15 bar and the time reaction was 2 hours. After the production of bio oil, it was filtrated and distillated, to work in the diesel range. Besides that, this oil was analyzed to determine two characteristics, flash point and specific mass, and with the result, we could evaluate the potential of coconut oil in the replacement of traditional fuels. The support s synthesis and the catalysts impregnation was considered satisfactory, because the results were presented according to the literature, showing that they are really mesoporous materials and besides that the presence of metals was proven. After characterization analyzes the bio oil produced by the nickel catalyst was considered the best, because your properties were within expected range (flash point equal 41 Celsius degrees and specific mass equal 0,8408 g/cm3 ), for a petroleum derived fuel, and had an efficiency of 45,05 percent in reducing oxygen concentration.