An alternative way of reporting on the redox behaviour of ceria-based catalytic materials:: Temperature-chemical environment-oxidation state diagrams

Temperature-chemical environment-oxidation state diagrams are proposed as an alternative way of reporting on the redox behaviour of ceria-based catalytic materials. In these diagrams, the changes occurred in the reduction degree of the investigated materials are plotted against temperature for different chemical atmospheres (5%O-2,/He, He, 5%H-2/Ar, and 5%CO/He). Compared to more conventional parameters like oxygen storage capacity, these diagrams allow us to gain a much wider view of the redox response of the investigated system. As an example, the diagrams are used to discuss the redox properties of two different ceria-terbia mixed oxide samples. (c) 2005 Elsevier B.V. All rights reserved.