Síntese de catalisadores baseados em óxido de ferro por processo sol-gel e sua aplicação em reações de oxidação seletiva de alcoóis

• Ano de defesa: 2017
• Autor(a) principal: Rossi, Marco Aurélio de Lima Silva
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Lavras; Programa de Pós-Graduação Multicêntrico em Química de Minas Gerais; UFLA; brasil; Departamento de Química
• Palavras-chave em Português: Processo sol-gel; Óxidos de ferro; Catálise heteogênea; Conversão de alcoóis; Sol-gel process; Iron oxides; Química
• Link de acesso: http://repositorio.ufla.br/jspui/handle/1/12361

Iron oxides based catalysts were synthesized by a sol-gel process based on Pechini’s method with some modifications to use cheaper and residual compounds as reagents and to obtain high pure materials. The oxides were characterized by X ray diffractometry (data treatment was made by Rietveld method refinement), scanning electron microscopy with energy-dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy. The catalysts were applied in gas phase selective oxidation of aliphatic alcohols. The catalytic process was investigated by chemometrics through experimental full factorial design and response surface methodology using the linear interaction model. The defined variables were temperature, ratio between citric acid and glycerol during the synthesis of the catalysts and number of carbons in the alcohols aliphatic chains. Ethanol, propranol and butanol were selected as model compounds for the conversion reactions. Significant conversions were obtained with maximum values near to 80% to butanol at 350ºC and expressive values to ethanol in all of the temperatures selected were verified (49% - 66%). Excellent selectivityof 100% for the corresponding aldehydes were achieved in all assays performed.