Nernstian Hydrogen Sensor Using BaCeO3 ‐ Based , Proton‐Conducting Ceramics Operative at 200°–900°C

A hydrogen concentration cell was constructed by using a high‐temperature, proton‐conducting oxide ceramic based on . This Nernstian hydrogen sensor gave rise to a stable electromotive force in correspondence to a hydrogen partial pressure, and the response speed was fast. Because of its high protonic conductivity, the working temperature range of the sensor was very wide, from 200° to 900°C. At 200°C, this sensor had a good selectivity to hydrogen.