Study on different CeO2 structure stability during ethanol steam reforming reaction over Ir/CeO2 nanocatalysts.

Structure stability of CeO 2 nanoparticles and nanorods were studied for ethanol steam reforming reaction over Ir/CeO 2 nanocatalysts. Characterizations of BET, XRD, HRTEM, H 2 -TPR and H 2 O-TPD et al. were applied to analyze surface areas, sizes, morphologies, redox properties and water activation of the nanocatalysts. Performance results revealed that reaction patterns of ethanol steam reforming reaction were dependent on the structures of CeO 2 supports, originating from different abilities in water activation. After long time stability tests conducted at high temperature of 923 K, the CeO 2 nanoparticles maintained original polyhedral shape, while the CeO 2 nanorods changed to polyhedrons. The shape variation of the nanorods was supposed to associated with OH groups combination and oxygen exchange in surface crystal planes of ceria nanorods, which diminished oxygen vacancies and reconstructed ceria morphology. [ABSTRACT FROM AUTHOR]