Esterificação do ácido mirístico com metanol sobre nanopartículas de titânia sulfatada
Biodiesel. Nano sulfated-titania. Esterification.
The search for renewable fuels has motivated the development of several studies in the field of catalysis. Within this context, biofuels have been the focus of several researches in Brazil and other major research centers. It is stood out that the use of biofuels can contribute to reduce environmental problems and dependence on conventional energy sources. Current research in the area of materials aimed at obtaining catalysts with high catalytic activity, enabling higher yield in the reaction and offering technical and environmental advantages. This way, aiming to contribute with previous studies in catalysis, this research aimed to synthesize nanoparticles sulfated titânia (TiO2/SO42-), by direct synthesis (TiO2/SO42- - SD)and postsynthesis methods (TiO2/SO42- - PS), to test its activity relative to the myristic acid esterification via methanolic. The catalysts were characterized by X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), nitrogen adsorption-desorption andtransmission electron microscopy(TEM). Alreadythe products obtainedby the esterificationwere characterizedby thin layer chromatography(TLC) and thermal analysis (TG / DTG and DSC). The XRD and Raman spectrum showed characteristic peaks of TiO2 and FTIR confirmed the presence of the sulfate group in samples obtained both by direct synthesis methods like the post synthesis. Relative to the isotherms, it was verified that the catalysts had mesoporous and microporous structures, it is being possible to estimate also showed that these size in nanometer dimensions. The same observation was checked by TEM. With regard to the products of catalysis, it was found that only the H2SO4, TiO2/SO42- - SD and TiO2/SO42- - PS showed activity and the late result evidenced higher conversion to ester (biodiesel).Therefore, it is concludedthat thesulfatationof thecatalystwas essentialfor the conversion ofmyristic acidinbiodieseland this activity,based on theliterature, it isassignedLewis andBrönsted´s acidity.