Aldol condensation between methanol and acetone, catalyzed by undoped and rare earths (Ce and Y) doped tin oxide nanoparticles is presented. Several methanol/acetone molar ratio conditions were evaluated aiming to produce methyl vinyl ketone as the main product. The undoped and doped ultrafine nanoparticles of tin oxide were prepared using the polymeric precursor method. The characterization was carried out by means of N2 adsorption (BET), X-ray diffraction (XRD), CO2 chemisorption, X-ray photoemission spectroscopy (XPS) and transmission electron microscopy (TEM). The catalytic behavior observed for SnO2 samples suggests that the methanol/acetone molar ratio and Ce and Y doping play an important role in the catalytic activity and in the product selectivity. The results from XRD and XPS pointed to the de-mixing process for the doped samples, due to the heat-treatment. This segregation layer contributes to the observed change in the catalytic behavior.
heterogeneous catalysis; aldol condensation; methyl vinyl ketone; tin oxide
