S?ntese e caracteriza??o de peneiras moleculares mesoporosas do tipo MCM-41 e AlMCM-41 a partir de fontes alternativas de s?lica e de alum?nio

• Main Author: Silva, Marta L?gia Pereira da
• Other Authors: CPF:06117988320
• Format: Others
• Language: Portuguese
• Published: Universidade Federal do Rio Grande do Norte 2014
• Subjects: S?ntese hidrot?rmica; MCM-41; AlMCM-41; Quartzo e aluminosilicato; Hidrot?rmico synthesis; Quartz and aluminosilicate mineral; CNPQ::ENGENHARIAS::ENGENHARIA DE MATERIAIS E METALURGICA
• Online Access: http://repositorio.ufrn.br:8080/jspui/handle/123456789/12736

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