Made available in DSpace on 2014-12-17T14:08:49Z (GMT). No. of bitstreams: 1 AruzzaMMA_DISSERT.pdf: 1774693 bytes, checksum: a3fe2aad8bc5ee5d62f0d84e6a4733c6 (MD5) Previous issue date: 2011-07-01 / The use of biofuels remotes to the eighteenth century, when Rudolf Diesel made the first trials using peanut oil as fuel in a compression ignition engine. Based on these trials, there was the need for some chemical change to vegetable oil. Among these chemical transformations, we can mention the cracking and transesterification. This work aims at conducting a study using the thermocatalytic and thermal cracking of sunflower oil, using the Al-MCM-41 catalyst. The material type mesoporous Al-MCM-41 was synthesized and characterized by Hydrothermical methods of X-ray diffraction, scanning electron microscopy, nitrogen adsorption, absorption spectroscopy in the infrared and thermal gravimetric analysis (TG / DTG).The study was conducted on the thermogravimetric behavior of sunflower oil on the mesoporous catalyst cited. Activation energy, conversion, and oil degradation as a function of temperature were estimated based on the integral curves of thermogravimetric analysis and the kinetic method of Vyazovkin. The mesoporous material Al-MCM-41 showed one-dimensional hexagonal formation. The study of the kinetic behavior of sunflower oil with the catalyst showed a lower activation energy against the activation energy of pure sunflower oil. Two liquid fractions of sunflower oil were obtained, both in thermal and thermocatalytic pyrolisis. The first fraction obtained was called bio-oil and the second fraction obtained was called acid fraction. The acid fraction collected, in thermal and thermocatalytic pyrolisis, showed very high level of acidity, which is why it was called acid fraction. The first fraction was collected bio-called because it presented results in the range similar to petroleum diesel / O uso dos biocombust?veis remota ao s?culo XVIII, quando Rudolf Diesel realizou os primeiros ensaios utilizando o ?leo de amendoim como combust?vel em um motor de igni??o por compress?o. Com base nesses ensaios, constatou-se a necessidade de realizar algumas transforma??es qu?micas ao ?leo vegetal. Dentre essas transforma??es qu?micas, pode-se citar a transesterifica??o e o craqueamento. Este trabalho tem como objetivo, realizar um estudo utilizando-se o craqueamento t?rmico e termocatal?tico do ?leo de girassol, utilizando o Al-MCM-41 como catalisador. O material mesoporoso tipo Al-MCM-41 foi sintetizado hidrotermicamente e caracterizado pelos m?todos de difra??o de raios-X, microscopia eletr?nica de varredura, adsor??o de nitrog?nio, espectroscopia de absor??o na regi?o do infravermelho e an?lise termogravim?trica (TG/DTG). Ainda foi realizado o estudo do comportamento termogravim?trico do ?leo de girassol sobre o catalisador mesoporoso citado. Com base nas curvas integrais das an?lises termogravim?tricas e o m?todo cin?tico de Vyazovkin, foram estimados a energia de ativa??o, a convers?o e a degrada??o do ?leo em fun??o da temperatura. O material mesoporoso Al-MCM-41 apresentou forma??o hexagonal unidimensional. O estudo do comportamento cin?tico do ?leo de girassol com o catalisador mostrou uma menor energia de ativa??o frente ? energia de ativa??o do ?leo de girassol puro. Na pir?lise t?rmica e termocatal?tica do ?leo de girassol foram obtidas duas fra??es l?quidas. A primeira fra??o obtida foi denominada de bio?leo e a segunda fra??o obtida foi denominada de fra??o ?cida. A fra??o ?cida coletada tanto na pir?lise t?rmica como na termocatal?tica apresentou ?ndice de acidez muito elevado, raz?o pela qual foi denominada fra??o ?cida. A primeira fra??o coletada foi denominada de bio?leo porque apresentou resultados na faixa semelhante ao diesel de petr?leo

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-05-30T22:35:16Z No. of bitstreams: 1 EnedersonRossetto_TESE.pdf: 3942346 bytes, checksum: 4f772d5bb76c7fedad3ac6471650a54d (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-06-01T20:17:58Z (GMT) No. of bitstreams: 1 EnedersonRossetto_TESE.pdf: 3942346 bytes, checksum: 4f772d5bb76c7fedad3ac6471650a54d (MD5) / Made available in DSpace on 2016-06-01T20:17:58Z (GMT). No. of bitstreams: 1 EnedersonRossetto_TESE.pdf: 3942346 bytes, checksum: 4f772d5bb76c7fedad3ac6471650a54d (MD5) Previous issue date: 2015-07-31 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Os ligantes ?-diiminas 2-(fenil)amino-4-(fenil)imino-2-penteno e o 2-(2,6-dimetilfenil)amino-4-(2,6-dimetilfenil)imino-2-penteno foram combinados com o grupo alcoxisilano cloropropiltrimetoxisilano (CPTMS) e ancorado covalentemente aos suportes mesoporosos MCM-41 e SBA-15, coordenados pela intera??o com os grupos silan?is da matriz das s?licas e complexados com n?quel. Os complexos Ni-?-diimina/mesoporosos foram sintetizados para aplica??o em rea??es de oligomeriza??o do etileno e do propileno e para compara??o dos resultados entre o sistema homog?neo com o sistema heterog?neo. O suporte foi primeiramente sintetizado e calcinado. Ap?s foi realizado o ancoramento dos ligantes e posterior complexac?o do n?quel. Estes materiais foram caracterizados por v?rias t?cnicas, tais como: RMN de 1H, 13C e 29Si, DRX de baixo ?ngulo, Infra-vermelho (IR), an?lise termogravim?trica, an?lise de isotermas de adsor??o-dessor??o de N2, microscopia eletr?nica de transmiss?o (MET) e de varredura (MEV), an?lise elementar e espectroscopia de absor??o at?mica para confirmar o sucesso das s?nteses dos materiais. Ambos os complexos homog?neos e os heterogeneizados s?o ativos e seletivos para as rea??es de oligomeriza??o do etileno e do propileno. Os materiais heterogeneizados foram menos ativos que os complexos an?logos homog?neos nas rea??es de oligomeriza??o do etileno, por?m, foram mais seletivos tanto para fra??es C4 quanto para ?-C4. Nas rea??es com o propileno os complexos homog?neos promoveram ? rea??o de dimeriza??o e os complexos heterogeneizados ? rea??o de alquila??o do tolueno com o propileno. / The ?-diimine ligands 2-(phenyl)amine-4-(phenyl)imine-2-pentene and 2-(2,6- dimethylphenyl)amine-4-(2,6-dimethylphenyl)imine-2-pentene were combined with the alkoxysilane group chloropropyltrimethoxysilane (CPTMS) and covalently anchored to a mesoporous MCM-41, Al-MCM-41 and SBA-15 support, ordered by interaction with the silanols of the silica matrix and complexed with nickel. The complexes were synthesized for application in ethylene and propylene oligomerization and for comparing results between homogeneous and heterogeneous systems. The support is first synthesized, calcined, anchored to the ligand, and then subsequent complexation of nickel is realized. These materials were characterized by several techniques such as 1H, 13C and 29Si NMR, small angle XRD, Infra-red, thermogravimetric analysis, nitrogen adsorption-desorption isotherms, transmission and scanning electron microscopy, elemental analysis, and flame atomic absorption spectroscopy, to confirm the success of the synthesis. Both homogeneous and heterogeneous complexes are active and selective for the reactions of ethylene and propylene oligomerization. The heterogenized materials were less active than the homogeneous analogous complexes in the reactions of oligomerization of ethylene, however, were more selective for both C4 fractions and for ?-C4. In reactions with propylene, the homogeneous complexes promoted the dimerization reaction and the heterogenized complexes the alkylation reaction of toluene with propylene complex.Complexes were tested in recycle reactions proved to be efficient for use in large scale.

[pt] A síntese de Fischer-Tropsch converte o gás de síntese (H2 + CO), em uma variedade complexa de hidrocarbonetos na presença de um catalisador (principalmente Co/Al2O3). Neste trabalho foram estudados catalisadores de Co e o Fe (1 e 5% em massa), incorporados aos suportes: zeólitas KL, HL 0,1M e HL 1,0 M, além da peneira molecular mesoporosa MCM- 41, pelo método de impregnação úmida incipiente, para a reação de Fischer- Tropsch. As amostras preparadas foram analisadas pelas técnicas de: Espectometria de Emissão Atômica de Plasma Acoplado Induzido, Adsorção Física de N2 pelo método BET, Difração de Raios-X, Redução com Temperatura Programada, Microscopia Eletrônica de Transmissão (MET), Quimissorção de Hidrogênio e Espectroscopia no Infravermelho de piridina adsorvida. Além disso, as amostras foram avaliadas em um reator de leito fixo na reação de Fischer-Tropsch. Para as amostras de ferro, com mesmo teor e suportes diferentes, pode-se observar que a amostra suportada na MCM-41 apresentou um grau de redução menor. Entre as amostras de ferro suportadas na KL, a 5% Fe/KL apresentou maior grau de redução e foi observado por microscopia eletrônica de transmissão (MET) que as partículas de ferro apresentaram diâmetro em torno de 6 nm. Para as amostras de cobalto foi observado que a temperatura de redução da amostra suportada na MCM-41 foi mais alta. A amostra 5% Co/KL apresentou um maior grau de redução. Foi possível observar por MET que as partículas de cobalto apresentaram diâmetro variando entre 8 e 20 nm. Verificou-se que o catalisador com maior teor de ferro proporcionou uma maior conversão de CO, tendo sido a distribuição de produtos deslocada para as frações mais leves. Comparando os catalisadores de ferro suportados na zeólita KL e na MCM-41 pode-se concluir que as conversões são da mesma ordem de grandeza. Foi observado que o ferro foi mais ativo que o cobalto em termos de conversão do CO, sendo que o cobalto promoveu a formação de uma maior quantidade de produtos na faixa de diesel, assim como uma menor quantidade de leves. / [en] The Fischer- Tropsch synthesis converts the synthesis gas (H2 + CO), in a complex variety of hydrocarbons, using a catalyst (Co/Al2O3 normally) were introduced to the used supports by the wetness incipient impregnation. The samples were analyzed by several techniques such as: plasma- emission spectrometry (ICP- EAS), N2 physical adsorption by BET method, X-ray diffraction (XRD), temperature programmed reduction (TPR), transmission electronic microscopy (TEM), hydrogen chemisorption and Infrared Spectroscopy of adsorbed pyridine. The catalysts were evaluated using a fixed bed reactor in the Fischer-Tropsch synthesis. For the iron samples, with the same metal content and different supports, it was observed that the MCM-41 sample presented the lowest reduction level. Among the iron samples supported in KL zeolite, the 5% Fe/KL sample presented the largest reduction level. It was observed by transmission electronic microscopy that the iron particles diameter measured around 6 nm. For the cobalt samples, it was observed that the reduction temperature of the MCM-41 supported was the highest one. The 5% Co/KL sample presented the largest reduction level. It was observed by TEM that the cobalt particles presented diameters in the range from 8 to 20 nm. It was verified that the catalyst with the largest iron percentage promoved the highest CO conversion. The products distribuition was shifted to light fractions. It was observed similar conversions to iron catalysts supported in the KL zeolite and in the MCM- 41 mesoporous molecular sieve. The iron catalysts were more active than the cobalt ones in the CO conversion, but tha cobalt catalysts promoted a higher content of diesel fraction and lesser light fractions.

Made available in DSpace on 2014-12-17T15:42:09Z (GMT). No. of bitstreams: 1 AnaCRM_TESE.pdf: 3734770 bytes, checksum: 59720290841ee6807d60b116e21f2090 (MD5) Previous issue date: 2010-12-06 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Microporous materials zeolite type Beta and mesoporous type MCM-41 and AlMCM-41 were synthesized hydrothermally and characterized by methods of X-ray diffraction, Fourier transform infrared, scanning electron microscopy, surface acidity, nitrogen adsorption, thermal analysis TG / DTG. Also we performed a kinetic study of sunflower oil on micro and mesoporous catalysts. The microporous material zeolite beta showed a lower crystallinity due to the existence of smaller crystals and a larger number of structural defects. As for the mesoporous materials MCM-41 and AlMCM-41 samples showed formation of hexagonal one-dimensional structure. The study of kinetic behavior of sunflower oil with zeolite beta catalysts, AlMCM-41 and MCM-41 showed a lower activation energy in front of the energy of pure sunflower oil, mainly zeolite beta. In the thermal cracking and thermocatalytic of sunflower oil were obtained two liquid fractions containing an aqueous phase and another organic - organic liquid fraction (FLO). The FLO first collected in both the thermal cracking as the thermocatalytic, showed very high level of acidity, performed characterizations of physicochemical properties of the second fraction in accordance with the specifications of the ANP. The second FLO thermocatalytic collected in cracking of sunflower oil presented results in the range of diesel oil, introducing himself as a promising alternative for use as biofuel liquid similar to diesel, either instead or mixed with it / Os materiais microporosos tipo ze?lita beta e mesoporosos tipo MCM-41 e AlMCM-41 foram sintetizados hidrotermicamente e caracterizados pelos m?todos de difra??o de raios X, infravermelho por transformada de Fourier, microscopia eletr?nica de varredura, acidez superficial, adsor??o de nitrog?nio, an?lise t?rmica via TG/DTG. Ainda foi realizado um estudo do comportamento cin?tico termogravim?trico do ?leo de girassol sobre os catalisadores micro e mesoporosos citados. Usando curvas integrais da TG e o m?todo cin?tico de Vyazovkin, foram estimados a energia de ativa??o, as taxas de convers?o e o tempo degrada??o do ?leo em fun??o da temperatura. O material microporoso ze?lita beta apresentou menor cristalinidade, devido ? exist?ncia de cristais menores e um maior n?mero de defeitos estruturais. Quanto aos materiais mesoporosos MCM-41 e AlMCM-41 apresentaram amostras com forma??o da estrutura hexagonal unidimensional. O estudo do comportamento cin?tico do ?leo de girassol com os catalisadores ze?lita beta, AlMCM-41 e MCM-41, mostrou uma menor energia de ativa??o frente a energia do ?leo de girassol puro, principalmente a ze?lita beta. No craqueamento t?rmico e termocatal?tico do ?leo de girassol foram obtidas duas fra??es l?quidas contendo uma fase aquosa e outra org?nica fra??o l?quida org?nica (FLO). A primeira FLO coletada, tanto no craqueamento t?rmico quanto no termocatal?tico, apresentou ?ndice de acidez muito elevado, sendo assim foi realizada as caracteriza??es das propriedades f?sico-qu?micas da segunda fra??o de acordo com as especifica??es da ANP. As segundas FLOs coletadas no craqueamento termocatal?tico do ?leo de girassol apresentaram resultados na faixa adequada ao diesel de petr?leo, apresentando-se como uma alternativa promissora para utiliza??o como biocombust?vel l?quido similar ao diesel, seja em substitui??o, ou misturado a este

Made available in DSpace on 2014-12-17T15:42:27Z (GMT). No. of bitstreams: 1 AlineAAO_TESE.pdf: 3075922 bytes, checksum: bd3bdc6aafacdcbe05784c0fbe751097 (MD5) Previous issue date: 2013-08-09 / The mesoporous nanostructured materials have been studied for application in the oil industry, in particular Al-MCM-41, due to the surface area around 800 to 1.000 m2 g-1 and, pore diameters ranging from 2 to 10 nm, suitable for catalysis to large molecules such as heavy oil. The MCM-41 has been synthesized by hydrothermal method, on which aluminum was added, in the ratio Si/Al equal to 50, to increase the generation of active acid sites in the nanotubes. The catalyst was characterized by X-ray diffraction (XRD), surface area by the BET method and, the average pore volume BJH method using the N2 adsorption, absorption spectroscopy in the infrared Fourier Transform (FT-IR) and determination of surface acidity with application of a probe molecule - n-butylamine. The catalyst showed well-defined structural properties and consistent with the literature. The overall objective was to test the Al-MCM-41 as catalyst and thermogravimetric perform tests, using two samples of heavy oil with API ? equal to 14.0 and 18.5. Assays were performed using a temperature range of 30-900 ? C and heating ratios (β) ranging from 5, 10 and 20 ?C min-1.The aim was to verify the thermogravimetric profiles of these oils when subjected to the action of the catalyst Al- MCM-41. Therefore, the percentage ranged catalyst applied 1, 3, 5, 10 and 20 wt%, and from the TG data were applied two different kinetic models: Ozawa-Flynn-Wall (OFW) and Kissinger-Akahrira-Sunose (KAS).The apparent activation energies found for both models had similar values and were lower for the second event of mass loss known as cracking zone, indicating a more effective performance of Al-MCM-41 in that area. Furthermore, there was a more pronounced reduction in the value of activation energy for between 10 and 20% by weight of the oil-catalyst mixture. It was concluded that the Al-MCM-41 catalyst has applicability in heavy oils to reduce the apparent activation energy of a catalyst-oil system, and the best result with 20% by weight of Al-MCM-41 / Os materiais mesoporosos nanoestruturados vem sendo estudados para aplica??o na ind?stria do petr?leo, em especial o Al-MCM-41, devido ? ?rea superficial em torno de 800-1000 m2g-1 e di?metro de poros variando de 2 a 10 nm, adequado para cat?lise de mol?culas grandes como petr?leos pesados. O MCM-41 foi sintetizado pelo m?todo hidrot?rmico, o qual foi adicionado Alum?nio numa propor??o Si/Al igual ? 50, a fim de aumentar a gera??o de s?tios ?cidos ativos nos nanotubos. O catalisador foi caracterizado por difra??o de Raios-X (DRX), ?rea superficial pelo m?todo BET e volume m?dio de poros pelo m?todo BJH atrav?s da adsor??o de N2, espectroscopia de absor??o na regi?o do infravermelho por Transformada de Fourier (FT-IR) e determina??o da acidez superficial com aplica??o de uma mol?cula sonda nbutilamina. O catalisador apresentou propriedades estruturais bem definidas e coerentes com a literatura. O objetivo geral foi testar o Al-MCM-41 como catalisador e realizar ensaios termogravim?tricos, utilizando duas amostras de petr?leo pesado com ?API iguais ? 14,0 e 18,5. Os ensaios foram realizados usando uma faixa de temperatura de 30 900?C, e raz?es de aquecimento (β) variando de 5, 10 e 20 ?Cmin-1. O intuito era verificar os perfis termogravim?tricos destes petr?leos quando submetidos ? a??o do catalisador Al-MCM-41. Para tanto, variou-se o percentual de catalisador aplicado in situ: 1, 3, 5, 10 e 20% em massa e, a partir dos dados termogravim?tricos foram aplicados dois modelos cin?ticos diferentes: Ozawa-Flynn-Wall (OFW) e Kissinger- Akahrira-Sunose (KAS). As energias de ativa??o aparente encontradas para ambos os modelos tinham valores semelhantes e eram menores para o segundo evento de perda de massa conhecido como zona de craqueamento, indicando uma atua??o mais efetiva do Al-MCM-41 nessa zona. Al?m disso, constatou-se uma diminui??o mais acentuada no valor das energias de ativa??o para valores entre 10 e 20% em massa da mistura catalisador-?leo. Concluiu-se que o Al-MCM-41 possui aplicabilidade catal?tica em petr?leos pesados diminuindo a energia de ativa??o aparente de um sistema catalisador?leo, sendo o melhor resultado com 20% em massa de Al-MCM-41

Hydrogen is considered as an alternative clean energy source due to the depletion of fossil fuels and related environmental problems. Steam reforming of bio-ethanol, has excellent potential for hydrogen production, with CO2 neutrality. Ni, Pd and Pt are the most active metals for steam reforming of ethanol. Improving catalytic activity of supported Ni catalyst by incorporating small amount of Pd or Pt is a successful method for increasing activity and stability of the catalyst. Development of active and stable catalysts with low coke formation and high hydrogen yield attracted major attention of researchers in recent decades. MCM-41 supported bimetallic mesoporous catalytic materials containing well dispersed Ni and Pd nanoballs were synthesized following an impregnation procedure. TEM images and XRD analysis of these materials indicated the formation of nickel and palladium nanoballs of 15-25 nm and 5-8 nm respectively, within the synthesized materials. These materials have quite narrow pore-size distributions in the range of 1-5 nm. In the calcined materials, nickel was in Ni+3 and Ni+2 states, however in the reduced sample most of the nickel was in Nio state, together with some NiO. Formation of NiOx crystals takes place after the calcination step. Impregnation of palladium into Ni/MCM-41 caused a decrease in the reduction temperature of NiO for about 50oC. Activity of the catalytic materials were tested in the reaction of steam reforming of ethanol.all the catalysts showed high conversion and quite high hydrogen yield over 400 oC. PdNi impregnated MCM-41 supported catalysts showed higher conversion of ethanol but lower hydrogen yield than Ni impregnated catalysts due to methane formation in the case of Pd incorporation. However, MCM-41 does not show enough hydrothermal stability for steam reforming of ethanol reaction. SBA-15 has very similar physical properties of MCM-41 with larger pores and high hydrothermal stability. Ceria also has widespread applications in catalysis area with its excellent oxygen buffering capacity. It can be used as catalyst support and also an improving agent for silica supports. Mesoporous silica SBA-15 with ordered pore structure was synthesized following a hydrothermal procedure and then bimetallic Ni-Ce and Pd-Ni-Ce incorporated mesoporous silica catalysts were prepared and tested in steam reforming of ethanol. On the other hand, ceria enriched silica structures i.e cerium/silicate composites were also synthesized. However the syntheses were unsuccessful due to the thermal sintering of ceria. Addition of ceria to the support structure decreased coke formation significantly.. According to the thermal gravimetric analysis studies conducted after ethanol steam reformin reaction at 600 oC, coke formation with Ni-SBA-15 (Ni/Si=0.10) catalyst was 40% and it was 10% with NiCe-SBA-15 (Ni/Si=0.10, Ce/Si=0.50) Activity test results obtained with Ni incorporated silica catalysts in steam reforming of ethanol gave high hydrogen yield over 4 (max. 6) and complete conversion of ethanol at 600 oC. SBA-15 found to be more stable catalyst than MCM-41 in the steam reforming of ethanol reaction. The highest hydrogen yield values were achieved by AlMCM-41 supported Ni-Ce impregnated catalysts. Aluminum in the slica matrix (3% wt.) increased the catalytic activity significantly, by giving acidic properties to the catalyst. Simultaneous and consecutive Ni and Ce impregnation were also examined. AlMCM-41 supported, consecutively Ce and Ni impregnated catalysts with Ce/Si and Ni.Si molar ratio sof 0.10, showed very high catalytic activity (5.8 at the beginning). AlMCM-41 supported catalyst were less stable because of high activity and consequently coke formation.

Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-04-30T16:37:00Z No. of bitstreams: 1 CLÁUDIA DOURADO MEDEIROS - DISSERTAÇÃO PPGEQ 2014..pdf: 1542895 bytes, checksum: 5a74f0ba9e6514c2859c363f528e0b6f (MD5) / Made available in DSpace on 2018-04-30T16:37:00Z (GMT). No. of bitstreams: 1 CLÁUDIA DOURADO MEDEIROS - DISSERTAÇÃO PPGEQ 2014..pdf: 1542895 bytes, checksum: 5a74f0ba9e6514c2859c363f528e0b6f (MD5) Previous issue date: 2014-04-02 / Capes / As peneiras moleculares mesoporosas possuem um arranjo hexagonal de mesoporos com diâmetros de poros que variam de 2 a 10 nm, possuindo assim uma área superficial elevada. A adição de um metal a sua estrutura tem como função gerar a acidez ao material o tornando mais reativo, aumentado assim a possibilidade do seu uso como catalisador na indústria do petróleo. Atualmente, um dos problemas encontrados pelos pesquisadores para obtenção desse tipo de peneira, é o longo tempo de formação das estruturas. No presente trabalho as peneiras moleculares mesoporosas MCM-41 e Al-MCM-41 foram sintetizadas utilizando dois processos hidrotermais, a tradicional e por micro-ondas, com o objetivo principal de reduzir o tempo de síntese do material. A peneira molecular MCM-41 foi sintetizada utilizando o processo hidrotermal tradicional, 100 oC por 48 horas , como também utilizando o processo hidrotermal de micro-ondas através de três metodologias, adotando diferentes tempos e temperaturas. Tomando como base os resultados obtidos com as sínteses da peneira molecular MCM-41 por meio do método hidrotermal de micro-ondas, os mesmos métodos foram aplicados para a peneira molecular Al-MCM-41 nas mesmas condições de tempo e temperatura. Através dos difratogramas foi possível perceber que a estrutura hexagonal foi formada. Verificouse que o melhor tempo de síntese da Al-MCM-41 se deu com 60 minutos a 130 oC. A partir destes dados, foram realizadas novas sínteses, reduzindo o tempo gradativamente. Os resultados das análises de DRX, MEV e FTIR comprovam que as peneiras moleculares mesoporosas foram formadas, sendo possível identificar sua estrutura e morfologia. Os melhores resultados de síntese para as peneiras moleculares mesoporosas MCM-41 e Al-MCM-41, foram nos tempos 60 e 40 minutos e temperatura de 130 oC, respectivamente. / The mesoporous molecular sieves have a hexagonal arrangement of mesopores with pore diameters ranging from 2 to 10 nm, which implies in a high surface area. The addition of a metal into these structures has the function of generating acidity in the material making it more reactive, increasing the possibility of using it as a catalyst into the oil industry. Nowadays, one of the problems found by researches to obtain these type of molecular sieves is the long time of structure formation taken by these materials. In this study, the mesoporous molecular sieves MCM - 41 and Al -MCM -41 were synthesized using two traditional microwave, with the primary goal of reducing the time of synthesis of the material hydrothermal processes. The molecular sieve MCM -41 was synthesized using the traditional hydrothermal process 100 °C for 48 hours , as well as hydrothermal process using microwave by three methods , adopting different times and temperatures . Based on the results obtained with the synthesis of molecular sieve MCM -41 by hydrothermal microwave method, the same methods were applied to the molecular sieve Al -MCM -41 under the same conditions of time and temperature. Through the DRX patterns was observed that the hexagonal structure was formed. It was found that the best time of synthesis of Al- MCM-41 was given 60 minutes at 130 oC. From these data, new syntheses were carried out by reducing the time gradually. The results of DRX, MEV and FTIR show that the mesoporous molecular sieves were formed, it is possible to identify their structure and morphology. The best results for the synthesis of mesoporous molecular sieves MCM - 41 and Al -MCM -41, were at times 60 and 40 minutes and temperatures of 130 °C, respectively.

Made available in DSpace on 2014-12-17T14:07:01Z (GMT). No. of bitstreams: 1 MartaLPS_partes_autorizadas_pelo autor.pdf: 1296900 bytes, checksum: ae142b4d715f0718971945acd4c853ad (MD5) Previous issue date: 2009-06-01 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / The mesoporous molecular sieves of MCM-41 and AlMCM-41 type are considered as promising support for metal in the refining processes of petroleum-based materials as catalysts and adsorbents for environmental protection. In this work the molecular sieves MCM-41 and AlMCM-41 were synthesized by replacing the source of silica conventionally used, for quartz, an alternative and abundant, and the use of waste from the production of diatomaceous earth, an aluminum-silicate, as a source aluminum, due to abundant reserves of diatomaceous earth in the state of Rio Grande do Norte in the city of Cear?-Mirim, with the objective of producing high-value materials that have similar characteristics to traditional commercial catalysts in the market. These materials were synthesized by the method of hydrothermal synthesis at 100 ? C for 7 days and subjected to calcination at 500 ? C for 2 hours under flow of nitrogen and air. The molecular sieves were characterized by X-ray diffraction (XRD), differential thermal analysis (DTA) and thermogravimetric analysis (TG), adsorption of N2 (BET and BJH methods), spectroscopy in the infra red (FTIR), microscopy scanning electron (SEM) and transmission electron microscopy (TEM). The analysis indicated that the synthesized materials showed characteristic hexagonal structure of mesopores materials with high specific surface area and sort and narrow distribution of size of pores / As peneiras moleculares mesoporosas do tipo MCM-41 e AlMCM-41 s?o consideradas promissoras como suporte para metais em processos de refino de materiais a base de petr?leo, como catalisadores e como adsorventes para prote??o ambiental. Neste trabalho foram sintetizadas as peneiras moleculares MCM-41 e AlMCM-41 atrav?s da substitui??o da fonte de s?lica convencionalmente utilizada, por quartzo, uma fonte alternativa e abundante, e pela utiliza??o do rejeito da produ??o de diatomita, um alumino-silicato, como fonte de alum?nio, devido a abundante reserva de diatomita no estado do Rio Grande do Norte, no munic?pio de Cear?-Mirim, com o objetivo de produzir materiais de alto valor agregado que apresentam caracter?sticas semelhantes aos catalisadores comerciais tradicionalmente existentes no mercado. Estes materiais foram sintetizados pelo m?todo de s?ntese hidrot?rmica a 100 ?C por 7 dias, e submetidos a calcina??o a 500 ?C por 2 horas sob fluxo de nitrog?nio e ar. As peneiras moleculares foram caracterizadas por difra??o de raios-X (DRX), an?lises t?rmicas diferencial (DTA) e termogravim?trica (TG), fisissor??o de N2, (M?todos de BET e BJH), espectroscopia na regi?o do infra vermelho (FTIR), microscopia eletr?nica de varredura (MEV) e microscopia eletr?nica de transmiss?o (MET). As an?lises indicaram que os materiais sintetizados apresentaram estrutura hexagonal caracter?stica dos materiais mesoporosos, com elevadas ordena??o e ?rea superficial espec?fica e estreita distribui??o de tamanho de poros

Une nouvelle approche de synthèse a été développée pour non seulement contrôler la morphologie, la taille et la texture de particules de silice mais aussi incorporer une ou plusieurs fonctionnalités à la surface interne de leurs pores. La morphologie sphérique, la monodispersité des particules, la porosité radiale, la dispersion et l'accessibilité des fonctionnalités ainsi que leur taux d'incorporation constituent les propriétés et les paramètres physico-chimiques privilégiés dans notre approche qui est basée sur la méthode de Stöber modifiée et la fonctionnalisation in-situ. Deux différentes applications ont été retenues pour étudier la quintessence de cette approche. La première consiste à incorporer des espèces métalliques (Al et Cu par exemple) dans les sphères de silice afin de les rendre fonctionnelles pour des applications catalytiques en phase liquide; et la deuxième consiste à greffer à la surface des particules des nanomachines sensibles permettant de contrôler le relargage des molécules actives pour des applications thérapeutiques. Dans les deux cas d'application, des performances optimales sont attendues. / A novel approach of synthesis has been developed in order to control simultaneously the morphology, size and textural parameters of silica particles, as well as to incorporate one or more functional groups in the pore walls. In this approach, based on the modified Stöber method and in-situ functionalization, emphasis is put on the spherical morphology, the particle monodispersity, the radially disposed porous structure, and the appropriate dispersion and accessibility of surface functional groups. Two potential applications have been selected so as to verify the feasibility of the approach. In view of materials use for heterogenous catalysis in the liquid phase, the monodisperses mesoporous silica spheres were derivatized with metallic species (e.g., Al and Cu) by direct incorporation in the synthesis stage. The second type of applications concerned the use of silica spheres as sensitive nanomachines for the controlled drug release and required grafting of appropriate organic molecules onto the silica surface.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Triazenes are a class of chemical compounds that presents three atoms of nitrogen bonded each other in sequence on a open chain. An analogue of these generics monocatenade Triazenes are Triazenes 1-oxide, used in many areas of chemistry, being targeted mainly in organic chemistry, analytical, medical, bioinorganic, coordination chemistry and catalysis recently. Was synthesized the free ligand 1-fenil-3-(4-Fluorophenil)Triazene N1-oxide (1) and from this, the complexes: bis[1-phenyl-3-(4-Fluorophenyl)triazene N1-oxide] Copper(II) (2), bis[1-phenyl-3-(4-Fluorophenyl)Triazene N1-oxide]Nickel(II) (3) and [1-phenyl-3-(4-Fluorophenyl)Triazene N1-oxide]-(triphenylphosphine)Gold(I) (4). The compounds were anchored on MCM-41, mesoporous molecular sieve with diameters between 2 and 50 nm , high surface area (1000 m2g-1) and high pore volume (1 cm3g-1), giving rise to solids Ligand-MCM (I), Cu-MCM (II), Ni-MCM (III) and Au-MCM (IV). The complexes and catalysts characterized by several types of analyzes such as melting point, infrared, x-ray diffraction powder and monocrystal, 1H and 13C NMR, nitrogen adsorption, TGA, among other. The solids were tested in the reactions oxidation of ciclooctene and reduction of chloro-cyclohexane to cyclohexane at different molar ratios (catalyst: oxidizing agent: substrate). This work has as main goal to discuss the crystallographic complex and present a comparison of efficiency among the catalysts supported on MCM-41. / Triazenos constituem uma classe de compostos químicos que apresentam três átomos de nitrogênio interligados de forma sequencial em uma cadeia aberta. Um análogo a este triazenos monocatenados genéricos, são os triazenos 1-óxido, utilizados em diversas áreas da química, sendo alvo principalmente na química orgânica, analítica, medicinal, bioinorgânica, química de coordenação e recentemente na catálise. Sintetizou-se o pró-ligante 1-fenil-3-(4-Fluorofenil)Triazeno N1-óxido (1) e a partir deste, os complexos: bis[1-fenil-3-(4-Fluorofenil)Triazeno N1-óxido]Cobre(II) (2) , bis[1-fenil-3-(4-Fluorofenil)Triazeno N1- óxido]Níquel(II) (3) e [1-fenil-3-(4-Fluorofenil)Triazeno N1-óxido]-(trifenilfosfina)Ouro(I) (4). Os compostos foram ancorados em MCM-41, uma peneira molecular mesoporosa com diâmetros de 2 e 50 nm, alta área superficial (1000 m2g-1) e elevado volume de poros (1 cm3g-1), dando origem aos sólidos Ligante-MCM (I), Cu-MCM (II), Ni-MCM (III) e Au-MCM (IV). Os complexos e catalisadores caracterizados por diversos tipos de análises, como por exemplo ponto de fusão, infravermelho, difração de raios X de pó e monocristal , RMN 1H e 13C, adsorção de nitrogênio, TGA , entre outros. Os sólidos foram testados nas reações de oxidação do cicloocteno e redução do cloro-cicloexano para cicloexano, em diversas proporções molares (catalisador:oxidante:substrato). Este trabalho tem como objetivo a discussão cristalográfica dos complexos e apresentar uma comparação de eficiência entre os catalisadores suportados em MCM-41.