YBaCo4O7+δ的制备及其氧吸附/脱附性能研究

Studies on Preparation and Adsorption/Desorption Properties of YBaCo4O7+δ

采用溶胶凝胶法和固态反应法制备了不同比表面积的YBaCo4O7＋δ吸附材料,采用X射线衍射仪、电子扫描显微镜对不同比表面积粒径的YBaCo4O7＋δ料的结构、形貌进行了表征,测试结果表明：溶胶凝胶法和固态反应法制备的YBaCo4O7＋δ料均为六方密排晶体结构（空间群为P63mc（186））,与固态反应法相比,溶胶凝胶法制备的YBaCo4O7＋δ吸附材料粒径较小,且分布较为集中,并研究了粒径对YBaCo4O7＋δ料氧吸附/脱附性能的影响,从室温到1000℃,不同粒径的YBaCo4O7＋δ吸附材料均经历两次氧吸附过程,而溶胶凝胶法制备的YBaCo4O7＋δ 料氧吸附性能明显高于固态反应法制备的YBaCo4O7＋δ料的氧吸附性能,这是因为溶胶凝胶法制备的YBaCo4O7＋δ料具有较小的尺寸,较大的比表面积的缘故。

YBaCo4O7＋δoxygen adsorption materials with different specific surface area were prepared by sol-gel method and solid state reaction method. Structure and morphology of YBaCo4O7＋δmaterials were investigated by XRD and SEM. XRD results show that YBaCo4O7＋δmaterials prepared via sol-gel method and solid state reaction method are single phase with the hexagonal crystal structure（space group P63 mc（186））. Compared with materials prepared via the solid-state reaction method, the YBaCo4O7＋δmaterials prepared via sol-gel process have smaller particle size and the distribution is relatively concentrated. TG analysis shows that all the samples with different particle sizes undergo two oxygen absorption processes from room temperature to 1000 ℃ and oxygen absorption property of YBaCo4O7＋δmaterials prepared via sol-gel method is larger than that of YBaCo4O7＋δprepared via solid state reaction. Due to its small size and large specific surface area, YBaCo4O7＋δpowder via sol-gel method has showed superior performance relative to the YBaCo4O7＋δvia solid state reaction.