EDTA-柠檬酸法合成的SrCo0.8Fe0.2O3-δ钙钛矿的结构及制氧性能研究
Oxygen production performance and structure of SrCo0.8Fe0.2O3-δ synthesized by combined EDTA-citrate complexing process
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摘要: 采用EDTA-柠檬酸联合络合法合成了钙钛矿型金属氧化物SrCo0.8Fe0.2O3-δ(SCF182)粉体。通过XRD和ESEM研究了前驱体溶液不同的pH值对合成的SCF182粉体的晶体结构和微观形貌的影响。并采用固定床实验研究前驱体溶液pH值对SCF182的氧吸附/脱附性能的影响。结果表明,pH值对SCF182晶胞结构和参数影响不大,但影响SCF182的晶粒粒径和微观形貌,当pH值为8的弱碱性条件下时,能够合成蓬松多孔网状纳米结构的钙钛矿粉体。固定床实验显示,前驱体溶液的pH值影响合成的粉体SCF182的氧吸附速率;且SCF182的氧脱附性能随pH值的增大先升高后降低,pH值为8时氧脱附量达到峰值为42.2 mg/g。Abstract: Perovskite-type metal oxides SrCo0.8Fe0.2O3-δ(SCF182) powder was synthesized by combined EDTA-citrate complexing process. The effects of the pH value of precursor solution on the crystal structure and morphology of synthesized SCF182 powder were investigated by X-ray diffraction and environmental scanning electron microscopy. Fixed-bed experiments were conducted to study the oxygen adsorption/desorption performance of SCF182. The results show that the pH values do not affect the forming of main crystal phase of SCF182 but affect the grain size and microstructure. The net-like porous structure is formed in the system when the pH value of the precursor is 8.The fixed-bed experimental results indicate that the pH value of precursor solution has effects on the oxygen adsorption reaction rate of SCF182. Furthermore, the maximum oxygen desorption amount of SCF182, 42.2 mg/g, can be obtained when the pH value is 8.