INCAPE   05401
INSTITUTO DE INVESTIGACIONES EN CATALISIS Y PETROQUIMICA "ING. JOSE MIGUEL PARERA"
Unidad Ejecutora - UE
artículos
Título:
Hydrogen production by ethanol steam reforming over Rh nanoparticles supported on lanthana/silica systems
Autor/es:
L. CORONEL, J.F. MÚNERA, A.M. TARDITI, L.M. CORNAGLIA; M.S. MORENO
Revista:
APPLIED CATALYSIS B-ENVIRONMENTAL
Editorial:
ELSEVIER SCIENCE BV
Referencias:
Lugar: Amsterdam; Año: 2014 vol. 160 p. 254 - 266
ISSN:
0926-3373
Resumen:
The aim of the present work was to investigate Rh nanoparticle catalysts
supported on La2O3-SiO2, with different
contents of La2O3 ,
in the ethanol steam reforming reaction. The size of Rh particles was
determined by both XPS, applying the Davis model, and CO chemisorption
measurements. Particle sizes between 1.2 and 3 nm were estimated with these
techniques. The catalyst with 15 wt. % of La2O3 was the
most stable one under the different reaction conditions under study, i.e. 773 K
and water to ethanol molar ratios of 3 and 5. In order to explain the
deactivation observed in the other catalysts, the samples used in the reaction
were characterized by XPS, TEM and in situ Raman spectroscopy. The TEM results
allowed a direct visualization of the carbon deposits that presented different
degrees of catalyst coverage. The
surface of the most stable catalyst was not fully covered by carbon while the Rh/ La2O3(40)-SiO2 sample,
which deactivated partially, exhibited a carbon layer uniformly distributed
over the surface. The oxidation of the
carbon deposits was analyzed using in situ Raman spectroscopy. Results were in
agreement with those obtained by TEM microscopy. DRIFTS experiments under reaction conditions suggested that the direct
decomposition of ethoxy species would produce hydrogen, CO, and CHx species,
which could result in carbon formation.