Preparation and performance study of Ba_(1-x)Sr_xCe_0.9Y_0.1O_3-δ (x = 0–0.5) proton conducting electrolytes

The preparation and properties of Ba_(1-x)Sr_xCe_0.9Y_0.1O_3-δ (x = 0–0.5) proton-conducting electrolytes have been investigated with the aim of developing an efficient membrane technology for hydrogen separation. This paper presents an investigation into the preparation and properties of proton-conducting electrolytes, with the objective of developing an efficient hydrogen separation membrane technology. Perovskite-structured electrolytes with varying Sr doping levels were successfully synthesized via solid-state sintering. The phase, microstructure, chemical stability, and conductivity properties of the materials were comprehensively characterized using XRD, SEM, and EIS. The experimental results demonstrate that as the quantity of Sr doping increases, the lattice parameter of the material decreases, the grain size increases, and the sample becomes dense. The results of the stability tests, conducted in an environment of 80 °C water and 700 °C CO₂, respectively, demonstrate that the introduction of Sr doping has a marked effect on the stability of the material when subjected to heated water; however, the impact of Sr doping on CO₂ stability is less pronounced. The conductivity test results show that the material with a doping level of 0 has the highest conductivity of 3.56 × 10⁻³–2.81 × 10⁻² S·cm⁻¹. In addition, the calculation results of carrier transport numbers indicate that the Ba_(1-x)Sr_xCe_0.9Y_0.1O_3-δ (x = 0–0.5) oxides are mixed protonic-oxide ionic-electronic conductors at 500–800 °C. The proton transport number increases with the increase of Sr doping, while the oxygen ion and electron hole transport numbers decrease, and Ba_0.5Sr_0.5Ce_0.9Y_0.1O_3-δ has the highest proton transport number which is 0.51 at 800 °C.