A New Strategy for Insight into the Dynamic Oxygen Migration in Metal Oxides

Oxygen migration in solid oxides affects material properties; however, a rigorous conceptual framework to quantify this dynamic process has been lacking. Herein, a dynamic oxygen migration-release model was developed using the differential element approach. This model revealed that the oxygen release rate of metal oxides decreases exponentially with the amount of released oxygen. And the migration processes of bulk oxygen and surface oxygen reactions were differentiated, and the energy barriers were determined. CeO 2 with various morphologies was used as a case study, showing differences in energy barriers between crystal facets. The adaptability of such an oxygen migration-release model can be expanded to other metal oxides, like ceria-zirconia solid solution, manganese oxide and iron oxide, increasing its potential universality. The oxygen migration-release law that has been found provides a theoretical foundation for the optimization methods of functional metal oxide materials, facilitating the assessment of oxygen reactivity within metal oxides.