High-temperature oxide ion and proton conductors play important roles in the development of technologies related to efficient and environment-friendly energy production e.g. as electrolytes, electrodes or as membranes for oxygen or hydrogen separation. The overall yield in these processes is determined either by surface reactions, by transport processes in the bulk of the oxides or by a combination of these.
While bulk transport kinetics in solid-state chemistry is understood to an advanced degree, the conceptional knowledge on surface kinetics and the relation between surface and bulk parameters is quite poor. This research project aims at contributing to bridge the gap between the level of understanding of surface and bulk kinetics.
About the project
Surface and bulk kinetics will be characterized by several transient techniques. The use of isotopes is central in the project. A novel technique where the use of isotopes in combination with mass spectrometry aims at determining the rate of surface dissociation, the surface exchange coefficient and the bulk diffusion coefficient is central. The project utilizes isotope annealing in combination with SIMS-profiling and, as such, strengthens the implementation of SIMS to research within high-temperature solid-state chemistry in Norway. In addition surface and bulk kinetics will be studied by transient thermogravimetry and transient conductivaity measurements. Surface characterization will, in general, be important and a large array of microscopy and spectroscopy techniques will be applied.
Overall, this project covers broader aspects than research confined to either surface or bulk kinetics. This approach is novel and, moreover, essential to succeed in reaching an improved understanding of the overall process. Such fundamental insight will serve as the bases for development of new and better materials for existing industrial processes, as well as for the design of new technologies.
The principal objective is to increase the fundamental understanding of surface processes and the linking between surface and bulk kinetics of high-temperature oxide ion and proton conductors; key knowledge to use these functional properties in technologies for an environment-friendly energy production.
- to measure surface kinetics of proton- and oxide ion conducting oxide systems
- to apply different experimental approaches where both surface and bulk properties can be extracted
- to determine and account for possible relations between surface and bulk kinetics on the overall behavior of oxide ion and proton conductors
- to study effects of surface texture, surface morphology and surface modifications in processes where surface kinetics is rate determining comprising systems from simple surfaces and model electrodes, to more complex three-dimensional electrode structures.
The project is funded by The Research Council of Norway through the FRINAT programme.