[en] In the present study aimed to evaluate the catalytic performance of NiFe₂O₄ and CoFe₂O₄ nanoferrites. The nanoferrites were synthetized using combustion reaction. The samples were characterized by X-ray diffraction, textural analysis, scanning electron microscopy, transmission electron microscopy and Fourier transform infrared spectroscopy. The cracking of the oil was conducted at 400 °C and at the end of the bio-oil obtained characterized as the acid value, kinematic viscosity, density and FTIR process. According to the results the combustion reaction synthesis allows obtaining nanoferrites with nanosized features with catalytic activity on reaction cracking thermo-catalytic. Among the catalysts evaluated nanoferrite NiFe₂O₄ showed better performance in the deoxygenation of bio-oil, thus resulting in a reduction in acid value of 53% on average. Bio -oil obtained from NiFe₂O₄ system, showed physicochemical characteristics near to S10 diesel. (author)

[en] Ni_0_._7Zn_0_._3Fe_2O_4 ferrospinel was synthesized by combustion and its catalytic performance in methyl and ethyl esterification of the soybean oil was investigated. The samples were characterized by X-ray diffraction, Rietveld refinement analysis, energy dispersive X-ray fluorescence spectroscopy, Fourier transform infrared spectroscopy, textural analysis, scanning electron microscopy, density by picnometry, particle size analysis, thermogravimetric analysis, magnetic measurements, and catalytic tests. The synthesis was efficient resulting in a ferrospinel with single phase Ni_0_._7Zn_0_._3Fe_2O_4 with crystallite size of 20 nm, high surface area (86 m"2/g) and saturation magnetization of 18 emu/g. The ferrospinel had promising catalytic activity in both reaction conditions studied, being more active in the conversion of soybean oil to biodiesel in methyl esterification with an average conversion of 93.9±2.8%. (author)