Characteristics of novel BaZr0.4Ce0.4In0.2O3 proton conducting ceramics and their application to hydrogen sensors

The characteristics of novel BaZr0.4Ce0.4In0.2O3 (BZCI) proton conducting ceramics and their application to hydrogen sensors were investigated. Their properties were examined by the EMF responses of a hydrogen concentration cell and an electrochemical hydrogen permeation test. The BZCI ceramic exhibited good proton conduction in an atmosphere containing hydrogen in the temperature range of 300–700 °C. To verify that these ceramics are practical protonic conductors, limiting-current-type hydrogen sensors using BZCI ceramics as electrolytes were constructed. They exhibited good sensing properties in a reducing atmosphere and hardly degraded on repeated use. BZCI seems to be a very useful protonic conductor in terms of reliability and conduction.