The Transport of Reducible Species Through a La0.8Sr0.2Cr03 Cathode in the High Temperature Electrolysis of Steam

IN THE FRAME OF A SYSTEMATIC RESEARCH DEVOTED TO THE HIGH TEMPERATURE STEAM ELECTROLYSIS, THE KINETIC BEHAVIOUR OF SOME CATHODIC LAYERS IN CONTACT WITH SOLID OXYGEN ION CONDUCTING ELECTROLYTE HAVE BEEN INVESTIGATED 1,2,3,4,5,6 BY DIFFERENT AUTHORS. IN PARTICULAR, IN OUR LABORATORIES THE KINETIC BEHA- VIOUR OF BOTH SINGLE AND DOUBLE LAYER ELECTRODES HAVE BEEN ANALYZED AND, AMONG THEM THE MIXED OXIDE LA0.8SR0.2CRO3 LOOKS INTERESTING BECAUSE OF ITS HIGH STRUCTURAL STABILITY. POLARIZATION EXPERIMENTS CARRIED OUT WITH SUCH MATERIAL SHOWED THE TRANSPORT OF REDUCIBLE SPECIES THROUGH THE OXIDIC LAYER COULD BE RATE DETERMINING THE OVERALL REACTION 7. THE ABOVE TO BE CLARIFIED, THE ELECTROCHEMICAL KINETICS OF THE STEAM REDUCTION AT THE INTERFACE BETWEEN ZIRCONIA AND LA0.8SR0.2CRO3 LAYERS OF DIFFERENT TICKNESS IN THE TEMPERATURE RANGE 1000 - 1300 K AND FOR DIFFERENT COMPOSITIONS OF H2/H2O MIXTURE HAS BEEN INVESTIGATED. PRELIMINARY RESULTS LOOK SURPRISING, AS IT CAME OUT ONLY A SLIGHT DEPENDENCE OF THE KINETIC PARAMETERS ON THE OXIDIC LAYER THICKNESS.

MARI C.M.; 

1995-03-15

JRC4872

https://publications.jrc.ec.europa.eu/repository/handle/JRC4872,