On the structure of vanadia supported on ceria nanoshapes

Journal Article · Sun Jan 01 04:00:00 EST 2012 · ChemCatChem

DOI:https://doi.org/10.1002/cctc.201200243· OSTI ID:1081909

Wu, Zili ^[1]; Li, Meijun ^[1]

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1. ORNL

Vanadia supported on ceria nanocrystals with defined surface planes, i.e., ceria nanoshapes including rods, cubes and octahedra were successfully synthesized. The effect of surface structure of these ceria nanoshapes on the structure of surface vanadia species as well as the formation of CeVO4 was investigated in details via in situ visible and UV Raman spectroscopy. The surface vanadia species on ceria nanoshapes evolve from monomeric vanadia to dimeric, trimeric, polymeric vanadia, and eventually crystalline V2O5 and CeVO4 as a function of vanadia loading. As expected, the nanoshaped ceria provides a rather homogeneous platform for anchoring vanadia, especially at low vanadia loading leading to only monomeric species, in contrast to the co-existence of different vanadia species on polycrystalline ceria even at extremely low vanadia loading. The formation of CeVO4 from the reaction between surface vanadia species and ceria was compared on the three ceria nanoshapes with similar surface vanadia density. It was found that both the surface structure and amount of defect sites of the ceria nanoshapes play major roles in the production of CeVO4. The easiest formation of CeVO4 on ceria rods is attributed to the lowest surface oxygen vacancy formation energy and the largest amount of defect sites available on the rods surface.

• Research Organization: Oak Ridge National Laboratory (ORNL); Center for Nanophase Materials Sciences
• Sponsoring Organization: SC USDOE - Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 1081909
• Journal Information: ChemCatChem, Journal Name: ChemCatChem Journal Issue: 10 Vol. 4; ISSN 1867-3880
• Country of Publication: United States
• Language: English

Related Subjects

vanadia ceria nanoshapes Raman surface structure defects CeVO4