本論文以含特定濃度之鋇、鍶、鈷與鐵等硝酸鹽溶液，加入碳酸銨溶液，在控制pH下，共沉獲得Ba0.5Sr0.5Co0.8Fe0.2O3 (BSCF氧化物)之碳酸鹽前驅物，經不同溫度煆燒所得粉末材料，製成固態氧化物燃料電池陰極，研究其結晶性質、表面形貌、電化學性質等，探討作為燃料電池陰極觸媒之可行性。結果顯示：含0.1M硝酸鋇、0.1M硝酸鍶、0.16M硝酸鈷與0.04M硝酸鐵溶液在加入飽和碳酸銨溶液，滴定至滴定終點為pH 8.0，過濾後得沉澱物，經1000℃煆燒2小時後獲得粉末，製成電池陰極。由場發射電子顯微鏡(FE-SEM)觀察陰極材料表面，顯示為多孔結構；X光繞射光譜儀(XRD)鑑定粉末晶體結構，顯示為純屬鈣鈦礦結構的Ba0.5Sr0.5Co0.8Fe0.2O3，未出現其他相。此種氧化物，經加入硝酸銀加溫，形成銀顆粒附著在BSCF氧化物顆粒上，所製成之固態氧化物燃料電池之陰極，其孔隙率由38.89 %降至33.74 %，因而影響到其陰極行為。 Carbonate precursor of Ba0.5Sr0.5Co0.8Fe0.2O3 (BSCF oxide) was prepared by chemical precipitation from a nitrate solution containing specific concentrations of barium, strongnium, cobalt and iron to react with a saturated solution of ammonium carbonate at various pH values. After filtration, the precipitate was calcined at different temperatures to form Ba0.5Sr0.5Co0.8Fe0.2O3 (BSCF oxide) powder that in turn was fabricated as the cathode catalyst. The surface morphology, crystalline structure and electrochemical property of the cathode catalyst were investigated prior to and post treatment with silver nitrate at elevated temperatures to estimate its cathodic catalyst used in the solid oxide fuel cells (SOFC). Resulting from chemical precipitation of a nitrate solution containing 0.1 M barium, 0.1 M strongnium, 0.16 M cobalt and 0.04 M iron reacted with a saturated solution of ammonium carbonate at pH equal to 8.0, the precipitate was filtered out, dried and calcined at 1000℃ for 2 h to attain the oxide powder. Through examination of FE-SEM, the calcined oxide revealed a porous morphology. Analysis of x-ray diffraction (XRD) displayed that the crystal of the oxide belonged to a perovskite of Ba0.5Sr0.5Co0.8Fe0.2O3 without presence of any detectable impurity. The oxide powder was fabricated into cathode catalyst which was treated with silver nitrate at elevated temperatures to study the effect of this treatment. Silver particles were coated on the BSCF oxide. It was found that the cathode catalyst decreased the porosity from 38.89% to 33.74 % after the treatment. It will influence its cathodic reactivity.
