Characterization of ceramic materials for electrochemical hydrogen sensors

Accurate and reliable tritium management is of basic importance for the correct operation conditions of the blanket tritium cycle. The Electrochemical Methods Lab at Institut Quimic de Sarria (IQS) is working in the design and development of tritium sensors, based on proton solid state electrolytes to be used in molten lithium–lead eutectic. Different solid electrolyte proton conductors have been synthesized (Sr3CaZr0.9Ta1.1O8.55, SrCe0.95Yb0.05O3−α, CaZr0.9In0.1O3−α, Ba3(Ca1.18Nb1.82)O9−α) in order to be evaluated in a testing apparatus for hydrogen gas. Potentiometric measurements of the synthesized ceramic elements have been performed. In all experiments the working temperature was 500 °C. The sensors constructed using the proton conductor element Sr3CaZr0.9Ta1.1O8.55 exhibited stable output potential and its value was close to the theoretical value calculated with the Nernst equation. When the proton conductor elements SrCe0.95Yb0.05O3−α and CaZr0.9In0.1O3−α and Ba3(Ca1.18Nb1.82)O9−α were used a deviation higher than 100 mV between theoretical and experimental data was obtained.