Impact of Ce-Fe synergism on the catalytic behaviour of Au/CeO2-FeO_x/Al2O3 for pure H2 production

摘要

In this work the development of a series of gold catalysts, essentially based on γ-alumina promoted with a small superficial fraction of Ce-Fe mixed oxides, is reported. The catalytic behaviour is evaluated in the water gas shift reaction. The formation of a Ce-Fe solid solution is evidenced by XRD and related to the catalytic activity where the importance of the Ce-Fe interaction is demonstrated. The best catalyst reached CO conversions very close to the equilibrium limit. A long-term stability test is performed and the loss of activity is observed and attributed to reaction intermediates. Almost complete recovery of the initial conversion is achieved after oxidation treatment, suggesting that the problem of stability could be overcome by a suitable change in the reaction parameters thus leading to a highly efficient catalyst for future applications in H2 production and clean-up.