Enhancing performance in important industrial catalysts
17 Jan 2019





​​Displacement of Ce and Nb in their cubic environment of 8 oxygens (red spheres) determined by modelling of neutron scattering data. The lower image shows a typical asymmetric Nb environment compared to the ideal site for the cation in CeO2, giving uncoordinated oxygen that explains the enhanced reducibility.​


​Ceria, cerium dioxide, has numerous applications in catalytic processes such as automotive emission control and hydrogen purification. Research is currently focusing on improving the oxygen storage capacity of the catalyst for new and emerging energy and environmental applications, and finding new methods for synthesising ceria. The inclusion of other metals can produce drastic improvements in the properties of ceria. A team of researchers has achieved partial substitution of cerium with niobium by also including sodium, via a low-temperature hydrothermal route. This process leads to thermally robust materials with oxygen storage capacities much greater than pure ceria. Neutron scattering on the GEM and Polaris instruments at ISIS was used to show how local structure may be dramatically disrupted by inclusion of substituent cations in this important class of materials, explaining their enhanced reducibility.

Related publication: C. I. Hiley et al. “Pair Distribution Function Analysis of Structural Disorder by Nb5+ Inclusion in Ceria: Evidence for Enhanced Oxygen Storage Capacity from Under-Coordinated Oxide" J. Am. Chem. Soc. 140(2018), 1588−1591, DOI: 10.1021/jacs.7b12421​

Contact: de Laune, Rosie (STFC,RAL,ISIS)