Hydrogen Permeation Properties of Ternary Ni–BaCe[sub.0.9]Y[sub.0.1]O[sub.3]–Ce[sub.0.9]Gd[sub.0.1]O[sub.2] Cermet Membranes

A ternary Ni–BaCe[sub.0.9] Y[sub.0.1] O[sub.3] (BCY)–Ce[sub.0.9] Gd[sub.0.1] O[sub.2] (GDC) cermet involving 40 vol% Ni was fabricated, and its hydrogen permeation characteristics were evaluated when the GDC volume fraction was varied from 0 to 30 vol%. The X-ray diffraction results of the cermet after sintering at 1400 °C revealed that GDC was dissolved in BCY when the GDC volume composition was 20 vol%. Regardless of the BCY and GDC volume fractions, the metal conductivity of the cermet was dominated by Ni. After the addition of only 1 vol% GDC, the particle sizes of Ni and BCY in the cermet significantly decreased, and the particle size decreased as the volume fraction of GDC increased. The hydrogen permeability increased with increasing temperature and for up to 10 vol% GDC, and a maximum permeation rate of 0.142 mL min[sup.−1] cm[sup.−2] was obtained at 700 °C. This value is comparable to or better than previously reported values for Ni-cermets under the same conditions. The amount of hydrogen permeation decreased above 10 vol% GDC. This study demonstrated that Ni-BCY-GDC cermet is a material that has both high hydrogen permeability and CO[sub.2] resistance.