Gas-phase selective conjugate addition of methanol to acetone for methyl vinyl ketone over SnO2 nanoparticle catalysts

• Autor(es):

  Fajardo, Humberto V. (Universidade Federal de Santa Catarina. Departamento de Química);

  Probst, Luiz F. D. (Universidade Federal de Santa Catarina. Departamento de Química);

  Valentini, Antoninho (Universidade Federal de Santa Catarina. Departamento de Química);

  Carreño, Neftalí L. V. (Universidade Federal de Sergipe. Departamento de Química);

  Maciel, Adeilton P. (Universidade Federal de São Carlos. Departamento de Química);

  Leite, Edson R. (Universidade Federal de São Carlos. Departamento de Química);

  Longo, Elson (Universidade Federal de São Carlos. Departamento de Química).

• Fonte:

  Journal of the Brazilian Chemical Society; volume 16, número 3b, páginas 607-613. Junho 2005.

• Assuntos:

  heterogeneous catalysis;

  aldol condensation;

  methyl vinyl ketone;

  tin oxide.

• Resumo:

  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.

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