INCAPE   05401
INSTITUTO DE INVESTIGACIONES EN CATALISIS Y PETROQUIMICA "ING. JOSE MIGUEL PARERA"
Unidad Ejecutora - UE
artículos
Título:
Catalytic activity vs. size correlation in platinum catalysts ofPEM fuel cells prepared on carbon black by different methods
Autor/es:
F. NORES-PONDAL; I.M.J. VILELLA; H. TROIANI; M. GRANADA; S.DE MIGUEL; O. SCELZA; H. CORTI
Revista:
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
Editorial:
Elsevier
Referencias:
Año: 2009 vol. 34 p. 8193 - 8203
ISSN:
0360-3199
Resumen:
In this work nanoparticulated platinum catalysts have been prepared on carbon Vulcan
XC-72 using three methods starting with chloroplatinic acid as a precursor: (i) formic acid
as a reductor agent; (ii) impregnation method followed by reduction in hydrogen atmosphere
at moderated temperature; and (iii) microwave-assisted reduction in ethylene
glycol. The catalytic and size studies were also performed on a commercial Pt catalyst
(E-Tek, De Nora).
The characterization of the particle size and distribution was performed by means of
transmission electron microscopy (TEM) and X-ray diffraction (XRD). The characterizations
of the catalytic and electrocatalytic properties of the catalysts were determined by studying
the cyclohexane dehydrogenation reaction (CHD) and the behavior under cyclic voltammetry
(CV) in sulfuric acid solutions. The measured electrochemical activity, along with the
hydrogen chemisorption of the catalysts allows the estimation of effective particle sizes,
which are much larger than those measured by TEM and XRD. The catalysts prepared by
reduction with formic acid and ethylene glycol (microwave-assisted) show electrochemical
activities very close to those of the commercial catalyst, and are almost insensitive to the
Pt dispersion or Pt particle size. The chemical activity in CHD correlates well with the
metallic dispersion determined by hydrogen chemisorption, indicating similar accesibility
of H2 and cyclohexane to the catalyst surface.2 and cyclohexane to the catalyst surface.