Solid oxide electrode kinetics in light of in situ surface studies

The combination of in situ and in particular in operando characterization methods such as electrochemical impedance spectroscopy (EIS) on both technical and model electrode are well known ways to gain some practical insight in electrode reaction kinetics. Yet, is has become clear that in spite of the strengths it is not sufficient to reveal much details of the electrode mechanisms mainly because it provide average values only.

Therefore it has to be combined with surface science methods in order to reveal the interface structure and composition. Ex situ methods have been very useful over the latest couple of decades, but recent in situ - or even better - in operando surface measurements such as high temperature scanning probe measurements and Raman spectroscopy have proven very valuable in obtaining new data that can support the interpretation of EIS and current – voltage (i-V) measurements.

Furthermore, it seems that detailed mathematical modeling using new tools like COMSOL is necessary for the synthesis of the large amount of data for a well-characterized electrode into one physical meaningful picture. A brief review of literature an own data will be presented with a practical example of SOFC investigations.