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Lehrstuhl für Physikalische Chemie

Research group: Functional ceramics for solid oxide fuel cells and solid oxide electrolyser cells

Head: Edith Bucher

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Working principle of SOFC (left) and SOEC (right).

Mixed ionic-electronic conduc­ting rare earth/alkaline earth transition metal oxides may play an important role in future energy systems. Applications include electrodes for solid oxide fuel cells (SOFCs) or solid oxide electrolyser cells (SOECs), oxygen permeable membranes, catalysts, and electrochemical sensors.

 

 

Schematics of oxygen exchange between gas phase and mixed conducting oxide.

The oxygen surface exchange kinetics of these materials is determined by the chemical composition of the surface, which may deviate significantly from the bulk composition. These differences are due to equilibrium effects or mechanical driving forces. The presence of critical reactants in the gas phase may represent an additional strong driving force for cation segregation effects and surface restructuring, leading to the formation of inactive phases in the near-surface region.

Crystal structure of La0.8Ca0.2FeO3-δ

Aims

Synthesis of novel functional oxides and comprehensive characterization of material properties.

New insights in relation of surface exchange kinetics of mixed ionic-electronic conducting rare earth/alkaline earth transitions metal oxides

Deeper understanding of structure-property relations of complex oxides to obtain guidelines on design of materials with optimized surface exchange and transport properties.

Design of new mixed ionic-electronic conducting oxides, which overcome current limitations imposed by insufficient activity and/or stability, is among the most fascinating tasks in the field of solid-state chemistry. Therefore, special emphasis is on synthesis and careful characterization regarding the complex interplay of a variety of parameters (crystal- and microstructure, defect chemistry, thermodynamics, kinetics, mass and charge transport properties, etc.).

Edith Bucher

Edith Bucher is Associate Professor at the Chair of Physical Chemistry at Montanuniverstitaet Leoben. Her research interests include synthesis and characterization of complex mixed ionic-electronic conducting oxides, structure-property relations of transition metal perovskites with focus on interrelation between surface oxygen exchange kinetics, surface microstructure, and surface chemical composition, and methodical development of in situ oxygen exchange measurements.

Her research group at the Chair of Physical Chemistry is internationally renowned for studies of surface oxygen exchange kinetics by in situ dc-conductivity relaxation measurements, including mechanisms of surface deactivation, and post-test analyses by complementary techniques on different length scales.