INVESTIGADORES
MORENO Mario Sergio Jesus
artículos
Título:
Hydrogen production by ethanol steam reforming over supported Rh nanoparticles on lanthanum silica binary systems
Autor/es:
L. CORONEL; J.F. MÚNERA; A.M. TARDITI; M.S. MORENO; L. CORNAGLIA
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
3nm 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.773K
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.