INVESTIGADORES
GUTIERREZ Victoria Soledad
artículos
Título:
Selective hydrogenation of cinnamaldehyde in supercritical CO 2 over Pt/SiO 2 and Pt/HS-CeO 2 : An insight about the role of carbonyl interaction with supercritical CO 2 or with ceria support sites in cinamyl alcohol selectivity
Autor/es:
CRISTIAN MARTÍN PIQUERAS; VICTORIA SOLEDAD GUTIERREZ; DANIEL VEGA; MARÍA ALICIA VOLPE
Revista:
APPLIED CATALYSIS A-GENERAL
Editorial:
ELSEVIER SCIENCE BV
Referencias:
Lugar: Amsterdam; Año: 2013 vol. 253 p. 253 - 260
ISSN:
0926-860X
Resumen:
The catalytic hydrogenation of cinnamaldehyde employing H 2 as the reductant was carried out under supercritical (sc) CO 2, propane and other CO 2 dense  mixture,  employing  Pt supported  on silica and  high  surface  (HS) ceria. The phase behavior of the mixtures was found to be in good agreement with the predictions obtained from the MHV2 (modified Huron-Vidal second-order) model. In order to study the influence of scCO 2 on the selectivity, the reaction was also conducted in dense propane and near-critical CO 2 -isopropanol mixtures.These results were compared with those corresponding to classical gas-liquid conditions with isopropanol as solvent and low H 2 pressure. In scCO 2 , the selectivity to cinnamyl alcohol over Pt/SiO 2 was 91%, quite higher than under classical conditions (38%). Such an enhancement is originated by the interaction of the C=O  with scCO 2 . For Pt/HS-CeO 2 the selectivity under supercritical conditions was slightly lower (80%) than the one corresponding to Pt/SiO 2 but quite higher than the one corresponding to  gas-liquid conditions (54%). The interaction of the carbonyl  group  with  ceria  support predominates in  this  case,  thus,  the  beneficial  effect  of scCO 2 is not observed in the same magnitude as in the case of Pt/SiO 2 . A catalytic scenario is drawn for each catalyst in order to explain the different selectivity patterns.