| Summary: | 碩士 === 國立交通大學 === 材料科學與工程學系所 === 101 === We demonstrate the preparation of BaCe0.4Zr0.4Gd0.1Dy0.1O3-δ (BCZGD) via a wet chemical route using precursors such as Ba(NO3)2, Ce(NO3)3‧6H2O, ZrO(NO3)4‧6H2O, Gd(NO3)3‧6H2O, and Dy(NO3)3‧5H2O. The synthetic process involves the dissolution of relevant precursors and glycine in deionized water at proper molar rations. Subsequently, the mixture undergoes a heat treatment at 1300°C for 10 hr in air to form the perovskite powders. The as-synthesized BCZGD powders are filtered and pressed at 440 MPa, followed by sintering at 1600°C for 24 hr in air to render a free-standing proton-conductive disk with a thickness of 500 μm. Material characterizations including scanning electron microscopy (SEM), X-ray diffraction (XRD), thermo-gravimetric analysis (TGA), and electrical conductivity measurements are performed. Diffraction patterns from the XRD indicate a perovskite structure without the appearance of undesirable phases. The electrical conductivity is recorded
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at 3.24×10-3 Scm-1 at 700°C in wet air with an activation energy of 0.37 eV. In a wet H2 atmosphere at identical temperature, its conductivity becomes 1.35×10-3 Scm-1 with an activation energy of 0.29 eV. Results from TGA analysis confirm that the BCZGD is chemically stable against CO2. Currently, the BCZGD samples are subjected to rigorous evaluations for their performances as a high-temperature membrane to separate CO2 and H2 for integrated gasification combined cycle (IGCC) power generation plant.
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