INCAPE   05401
INSTITUTO DE INVESTIGACIONES EN CATALISIS Y PETROQUIMICA "ING. JOSE MIGUEL PARERA"
Unidad Ejecutora - UE
artículos
Título:
Cobalt nanoparticles on mesoporous MCM-41 and Al-MCM-41 by Supercritical CO2 Deposition
Autor/es:
ASPROMONTE, SOLEDAD; SASTRE, ALVARO; BOIX, ALICIA; COCERO, MARÍA JOSÉ; ALONSO, ESTHER
Revista:
MICROPOROUS AND MESOPOROUS MATERIALS
Editorial:
ELSEVIER SCIENCE BV
Referencias:
Lugar: Amsterdam; Año: 2012 vol. 148 p. 53 - 61
ISSN:
1387-1811
Resumen:
CoO and Co3O4 nanoparticles were uniformly dispersed inside mesoporous MCM-41 and Al-MCM-41
supports using supercritical CO2 reactive deposition. This method represents a one-pot reproducible procedure
that allows the dissolution of the organocobalt precursor and supports impregnation in supercritical
CO2 at 70 _C and 110 bar, followed by the precursor thermal decomposition into cobalt species at
200 _C and 160 bar. By the relative concentration of the cobalt precursor [cobalt (II) bis (g5-ciclopentadienil)],
the load of cobalt nanoparticles was controlled and then determined by Inductively Coupled
Plasma (ICP-OES). The synthesis of CoO and Co3O4 species inside the MCM-41 and Al-MCM-41 substrates
was confirmed by X-ray Photoelectron (XPS) and Laser Raman Spectroscopies (LRS). By N2 adsorption and
Small Angle X-ray Scattering (SAXS), it was determined that the hexagonal arrangement as well as the
surface area and pore size of the substrates changed after the addition of cobalt. By means of X-ray mapping
from SEM images, a homogeneous distribution of cobalt nanoparticles was observed inside the mesopores
when the cobalt loading was 1 wt.%. In addition, spherical cobalt nanoparticles of average
diameter close to 20 nm were detected on the outer surface of MCM-41 and Al-MCM-41 supports when
the cobalt content was higher. On the other hand, by Transmission Electron Microscopy (TEM), it was
possible to measure the interplanar distance of the crystalline plane of the outer nanoparticles, which
was later compared with the theoretical distance values which allowed identifying the CoO and Co3O4
phases