Investigation on preparation and properties of the dual-phase proton conductor BaCe_(0.9)Y_(0.1)O_(3-δ)/La_(1.95)Ca_(0.05)Ce_2O_(7-δ)

The dual-phase proton conductors BaCe0.9Y0.1O3-δ-La1.95Ca0.05Ce2O7-δ(7∶3,6∶4,5∶5,4∶6,3∶7) were successfully synthesized by the solid state reaction method.The phase composition and microstructure of the samples were investigated by XRD and SEM.Chemical stability against CO2 and boiling water was tested.The total conductivities of the samples in air,Ar and wet 4%H2/Ar from 450℃ to 850℃ were measured by IM6e electrochemical workstation.The results indicate that the samples sintered at 1500℃ with different ratio consist of the BaCe0.9Y0.1O3-δ and La1.95Ca0.05Ce2O7-δ dual-phase composition and the samples are very dense after sintered.With La1.95Ca0.05Ce2O7-δ content increase in BaCe0.9Y0.1O3-δ-La1.95Ca0.05Ce2O7-δ dual phase samples,the samples show an increased chemical stability against CO2 and boiling water.The sample with BaCe0.9Y0.1O3-δ-La1.95Ca0.05Ce2O7-δ(3∶7) has the highest conductivity among the samples and its conductivity is 2.49×10-2S/cm at 850℃ in wet 4%H2/Ar.Its conducting activity energy is 1.13eV.