Effect of Ce/Zr ratio in CeZr-CoRh catalysts on the hydrogen production by glycerol steam reforming

Authors: L.M. Martínez T, M. Araque, J.C. Vargas, A.C. Roger

Abstract:
The H₂ production by glycerol steam reforming has been studied using fluorite-type mixed oxides of CZCoRh. The effect of the Ce/Zr ratio on the catalytic properties and its influence on the catalytic behavior are discussed. The catalysts were characterized before and after catalytic test by XRD, Raman spectroscopy, BET surface area, HRTEM, H₂-TPR and TPD-TPO. The results show that an increase of the cerium amount enhances both the stability and the selectivity toward H₂ and CO₂. This is related to the improvement of the reducibility and re-oxidation properties, oxygen storage capacity and metal support interaction. The activity results demonstrate that selective H₂ production is related to the capacity of the catalysts to activate H₂O under reaction conditions. This step ensures the steam reforming of the by-products to H₂. The progressive loss of this capacity reduces the H₂ production, decreasing the steam reforming ability and the glycerol decomposition becomes predominant. In this last case the production of CO, CH₄ and C₂H₄ is promoted along with the formation of condensable products as hydroxyacetone, acetaldehyde and acrolein.

Keywords:
Glycerol
Hydrogen production
Steam reforming
Mixed oxides
Rhodium catalysts
Cobalt catalysts
Glycerol decomposition

Published in: Applied Catalysis B: Environmental (Volumes 132–133, Pages 1-552, 27 March 2013)

Publisher: Elsevier  

ISSN Information: 0926-3373

Effect of Ce/Zr ratio in CeZr-CoRh catalysts on the hydrogen production by glycerol steam reforming

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