Selective synthesis of vinyl ketone over SnO2 nanoparticle catalysts doped with rare earths

Ultrafine particles of tin oxide, doped with the rare earths Ce, Y and La respectively, were prepared using the polymeric precursor method. The novel application of nanostructured tin oxide, undoped and doped, to the C-C bond formation of an alpha,beta-unsaturated compound (methyl vinyl ketone; MVK) is presented. The promotion of SnO2 by rare earths results in a large increase in the catalytic activity and basicity (total basic sites). The catalytic behavior observed in SnO2 samples suggests that the control of the catalytic activity and the selectivity of the products takes place by the segregation of a layer of a rare earth compound, with the increase of the heat-treatment temperature. The structural variations of the ultrafine particles were characterized by means of BET, XRD, CO2 chemisorption and Raman. (C) 2003 Elsevier B.V. All rights reserved.