Effect of Pr and In doping on hydrogen permeability properties of Y-BaZrO3

Y-doped BaZrO 3 has emerged as a promising ceramic material for hydrogen separation membranes. The conductivity of Y-BaZrO 3 (BZY) ceramics is highly dependent on the concentration of oxygen vacancies. In this work, BZY further individually doped with In and Pr were prepared by the citrate sol–gel combustion method. Effects of doping on the ceramic phase structure, oxygen vacancies, and micromorphology were investigated using a range of analytical techniques, including XRD, Raman spectroscopy, XPS, and SEM. The conductivity, hydrogen permeability, and stability of BaZr 0.7 Y 0.2 In 0.1 O 3−δ (BZYI) and BaZr 0.7 Y 0.2 Pr 0.1 O 3−δ (BZYP) ceramics were systematically evaluated. Upon doping, BZYI exhibits the most favorable conductivity, reaching 9.98 × 10 −3 S·cm −1 in dry air at 800 °C. At 900 °C, with water vapor introduced on the sweep side, the hydrogen permeation fluxes of BZYI and BZYP are 3.50 × 10 −9  mol·cm −2 ·s −1 and 2.60 × 10 −9  mol·cm −2 ·s −1 , respectively. Both samples were exposed to boiling water and a 100% CO 2 atmosphere at 900 °C for 3 h. Post-treatment XRD, Raman, and SEM analyses reveal no formation of heterophase, indicating excellent phase and microstructural stability.