Síntese e caracterização dos coprecipitados de cálcio e alumínio com 8-hidroxiquinolina e avaliação catalítica na reação de transesterificação

Abstract

The present study aimed to synthesize and evaluate the activity catalytic in the reaction transesterification of the material formed after decomposition thermal of coprecipitated of calcium and aluminum with 8-hydroxyquinoline. The synthesis of the material was performed by method coprecipitation using as agent precipitating 8-hydroxyquinoline. To evaluate the presence of metal calcium and aluminum on the characteristics of the material, we used different percentages of these metals in the synthesis of complexes using the same conditions reaction, with a pH final of 10 to temperature of 25 ºC. After synthesis the complexes were characterized by scanning electron microscopy, infrared spectroscopy, and thermal analysis in synthetic air atmosphere at heating rates of 5 °C, 10 °C and 20 ºC min-1. Through the curves TG, DTA and DTG was found that the presence of metal aluminum promoted process partial of sublimation the material. The materials obtained after analysis thermal were characterized by scanning electron microscopy, not observed changes significant in morphology between the different reasons heating. For review catalytic on reaction transesterification used a ratio molar of acetate ethyl:methanol 1:6, temperature 50 °C, time reaction 1 hour to 1% catalyst, the catalyst being obtained at temperature a calcination of 700 °C with a rate heating 10 ºC min-1. The highest conversion (0.98%) was obtained from the material synthesized with 100% metal calcium in its formulation, but the conversions are low seen partially due to the conditions mild used.