Chemical stability and electrical conductivity of BaCe0.4Zr0.4Gd0.1Dy0.1O3−δ perovskite

A proton-conducting BaCe0.4Zr0.4Gd0.1Dy0.1O3−δ (BCZGD) perovskite is fabricated via a wet chemical route using precursors including Ba(NO3)2, Ce(NO3)3·6H2O, ZrO(NO3)4·6H2O, Gd(NO3)3·6H2O, and Dy(NO3)3·5H2O. The synthesis process involves the dissolution of relevant precursors and glycine in deionized water at proper molar ratios. Subsequently, the mixture undergoes a heat treatment at 1300 °C for 10 h in air to form the perovskite powders. The as-synthesized BCZGD powders are filtered and pressed at 440 MPa, following by a sintering at 1450 °C for 24 h in air to render a free-standing proton-conductive disk with a thickness of 850 μm. Material characterization including scanning electron microscopy (SEM), X-ray diffraction (XRD), thermo-gravimetric analysis (TGA), and electrical conductivity measurements are performed. The electrical conductivity of the BCZGD sample is recorded at 1.93×10−3 S cm−1 at 700 °C in a humid hydrogen atmosphere with an activation energy of 0.41 eV. TGA results confirm chemical stability of the BCZGD against carbon dioxide without any decomposition.