Navegando por Autor "Mignoni, Marcelo Luis"
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Artigo Nickel oligomerization catalysts heterogenized on zeolites obtained using ionic liquids as templates(Elsevier, 2010-02-01) Mignoni, Marcelo Luis; Souza, Michèle Oberson de; Pergher, Sibele Berenice Castellã; Souza, Roberto Fernando de; Bernardo-Gusmão, KatiaSynthesis of zeolites using 1-butyl-3-methylimidazolium chloride (BMI.Cl) as a template yields highly crystalline materials after a 3-day reaction time. SEM micrographs of material obtained with a Si/Al molar ratio of 50 showed formation of very regular microspherical agglomerates with approximate diameters of 30 μm composed of ZSM-5 crystallites with 3–5 μm long edges. The regular format of these crystallites has been attributed to the formation of micellar aggregates due to the ionic liquid. Decreasing the Si/Al molar ratio to 20 reduces the diameter of the microspheres to less than 1 μm. The ZSM-5 zeolites show a specific area of 384 m2 g−1 and a microporous volume of 0.10 cm3 g−1, and the β-zeolite, obtained after 7 days of crystallization, shows a specific area of 418 m2 g−1 and a microporous volume of 0.11 cm3 g−1. The β-zeolite was used as support for a nickel β-diimine complex and the system used in ethylene catalytic oligomerization reactions.Dissertação Síntese de zeólitas tipo ton utilizando um sal de imidazólio como agente direcionador de estrutura(Universidade Federal do Rio Grande do Norte, 2014-05-23) Lopes, Christian Wittee; Pergher, Sibele Berenice Castella; ; http://lattes.cnpq.br/5249001430287414; ; http://lattes.cnpq.br/4953371870936050; Pastore, Heloise de Oliveira; ; http://lattes.cnpq.br/3259546601542310; Mignoni, Marcelo Luis; ; http://lattes.cnpq.br/4100312412618474; Nuñez, Alejandro Eusebio Rojas; http://lattes.cnpq.br/2543815919001659Este trabalho relata a síntese de zeólitas de diferentes composições (puramente silícicas, Si/Ti e Si/Al), via meio básico e fluorídrico, utilizando o cátion 1-butil-3- metilimidazólio como agente direcionador de estrutura. Inicialmente o cátion foi sintetizado e utilizado na forma de cloreto para as sínteses em meio básico e uma troca aniônica (Cl- para OH-) foi necessária para as sínteses em meio fluorídrico. Diferentes reagentes foram empregados para a formação dos géis de síntese, resultando na cristalização das fases MFI e TON, esta última predominante em muitas composições de gel testadas. O cátion sintetizado e as zeólitas obtidas foram caracterizados por diferentes técnicas, como RMN, TG/DTG, DRX, MEV, adsorção e dessorção de N2, DRS e EPMA. Além de caracterizar o cátion e as zeólitas, a água-mãe das sínteses em meio básico foi caracterizada e foi possível verificar uma modificação do cátion nas condições de síntese empregadas. Os materiais sintetizados neste trabalho podem ser aplicados em reações catalíticas e de adsorçãoArtigo Synthesis and Characterization of Al-TON Zeolite Using a Dialkylimizadolium as StructureDirecting Agent(Scielo, 2016-11-07) Pergher, Sibele Berenice Castellã; Lopes, Christian Wittee; Villarroel-Rocha, Jhonny; Silva, Bernardo Araldi da; Mignoni, Marcelo LuisIn this work, the synthesis of zeolites using 1-butyl-3-methylimidazolium chloride [C4MI]Cl as a structure-directing agent was investigated. The organic cation shows effectiveness and selectivity for the syntheses of TON zeolites under different reaction conditions compared to the traditional structuredirecting agent, 1,8-diaminooctane. The 1-butyl-3-methylimidazolium cation lead to highly crystalline materials and its role as OSDA in our synthesis conditions has been confirmed by characterization techniques. ICP-OES confirms the presence of Al in the samples and 27Al MAS NMR analysis indicated that aluminum atoms were incorporated in tetrahedral coordination. Scanning electron microscopy indicated that changing the crystallization condition (static or stirring), zeolites with different crystal size were obtained, which consequently affects the textural properties of the zeolites. Moreover, varying some synthesis parameters MFI zeolite can also be obtainedArtigo TiO2-TON zeolite synthesis using an ionic liquid as a structure-directing agent(Elsevier, 2015-09-01) Lopes, Christian Wittee; Finger, Pedro Henrick; Mignoni, Marcelo Luis; Emmerich, Daniel J.; Mendes, Fabiana Magalhães Teixeira; Amorim, Stefany; Pergher, Sibele Berenice CastellãThe 1-butyl-3-methylimidazolium chloride ionic liquid was employed as a structure-directing agent for the preparation of TiO2-TON zeolites under different crystallization conditions. By varying the crystallization parameters (i.e., time, structure-directing agent, and TiO2 content), the ionic liquid was determined to be a powerful structure-directing agent for the TON zeolite, which was confirmed by 13C NMR. In both stirring and static modes, the TON zeolites crystallize. The analysis of the X-ray diffraction data indicated that the synthesized materials are highly crystalline. X-ray photoelectron spectroscopy analyses indicated that titanium elements were present in an octahedral (anatase) and tetrahedral (bridging the zeolitic structure) environment. Electron probe microanalysis indicated a good distribution of titanium in the crystals, possessing rice grain morphology that is characteristic of this zeolitic structure. The ionic liquid was modified during hydrothermal synthesis, and further investigation regarding its possible reuse as a structure-directing agent will be conducted