MICROWAVE-ASSISTED HYDROTHERMAL SYNTHESIS OF Ni-DOPED SnO2 NANOPARTICLES AND THEIR USE AS CATALYSTS IN BIODIESEL PRODUCTION

Abstract

The high chemical stability and low cost of tin dioxide has been widely reported in the literature, as has its microwave-assisted hydrothermal synthesis. The use of heterogeneous catalysts in biodiesel synthesis has proved very promising, with conversion rates exceeding 80%. The purpose of this study was to synthesize Ni-doped SnO2 for application as a heterogeneous catalyst in the transesterification of vegetable oils. The powders were characterized by X-ray diffraction, Raman spectroscopy, scanning electron microscopy and N-2(g) adsorption/desorption using the Brunauer-Emmet-Teller (BET) method. The results revealed powders with nanometric agglomerates and high surface areas. Catalytic tests revealed an 80% retention factor and a decrease in the viscosity of babassu oil from 30.27 mm(2) s(-1) to 6.91 mm(2) s(-1), indicating that the synthesized catalyst can be used in the transesterification of vegetable oils.