Hydrogen production from ethanol steam reforming over Ir/CeO2 catalysts: Enhanced stability by PrOx promotion

We studied ethanol steam reforming over Ir/Ce0.9Pr0.1O2 and Ir/CeO2 catalysts comparatively with respect to activity and stability. We found that PrOx-doping have significantly promoted the oxygen storage capacity and thermal stability of the catalysts by incorporation into the ceria lattice. Ethanol was readily converted to hydrogen, methane and carbon oxides at 773 K over the Ir/Ce0.9Pr0.1O2 catalyst, and this is 100 K lower than that found for the Ir/CeO2 catalyst. Moreover, the PrOx-doped catalyst was stable toward ethanol steam reforming at 923 K for 300 h without an apparent variation in ethanol conversion and product distribution. However, the severe aggregation of ceria particles and heavy coke deposition were observed on the Ir/CeO2 catalyst, resulting in remarkable deactivation under the same reaction conditions.

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► Ir/Ce0.9Pr0.1O2 has higher oxygen storage capacity and thermal stability than Ir/CeO2.
► PrOx-doping generates more oxygen vacancies through the formation of solid solution.
► Ethanol is fully converted to hydrogen and C1 products at 773 K on Ir/Ce0.9Pr0.1O2.
► Ir/Ce0.9Pr0.1O2 was rather stable for 300 h without obvious deactivation at 923 K.