ABSTRACT

The magnitude of the activation overpotential for an electrocatalytic reaction occurring at the electrode/solid electrolyte tpb or interface depends crucially on the exchange current density i0. The exchange current density i0 is a measure of the electrocatalytic activity of the tpb or, more generally, the electrode/solid electrolyte interface for a given electrocatalytic reaction. The interesting role which solid electrolytes can play in the study of heterogeneous catalysis was first recognized by Wagner, who proposed the use of solid electrolyte cells for the measurement of the activity of oxygen on metal and metal oxide catalysts. Electrocatalysis plays an important role in the efficient operation of solid electrolyte fuel cells used for power generation. Catalysis at the anode also has a significant role. Electrocatalysis in solid electrolyte cells can also be used to activate catalysis on the gas-exposed electrode surfaces. This novel application of solid electrolytes is of great importance both in electrochemistry and in heterogeneous catalysis.