Isotopic effect of proton conductivity in barium zirconates for various hydrogen-containing atmospheres

Among various perovskite proton conducting oxides, Y-doped BaZrO3 perovskite is a promising material for electrochemical hydrogen devices due to its good chemical stability and higher proton conductivity at higher operating temperatures like 500–800 °C. For the practical application of the functional BaZrO3 proton conductors in electrochemical hydrogen devices like tritium purification and recovery systems in a nuclear fusion reactor (where deuterium and tritium isotopes are utilized as fuel), it’s necessary to understand the isotopic effect of proton conductivity. To understand the isotopic effect of proton conductivity in the barium zirconates, in this study, the proton conductivities in the Ar, (Ar + 4% H2), (Ar + 4% D2), (Ar + H2O), (Ar + D2O), and O2 atmospheres were measured for two different compositions: BaZr0.9Y0.1O2.95 (BZY), and BaZr0.955Y0.03Co0.015O2.97 (BZYC) in the temperature range from 500 °C to 1000 °C. By comparing the obtained results, a significant difference in sinterability, conductivity, and the isotopic effect was observed due to the co-doping of the Co element in the BaZr1−xYxO3-α proton conductor.