PMMA模板制备LaMnO_(3)及其电化学性能研究

Study on catalytic performance of LaMnO_(3) prepared byPMMA template method for oxygen reduction

采用PMMA(聚甲基丙烯酸乙酯)根据Stober-Frink法制备出PMMA微球,并将其作为模板剂,以柠檬酸为络合剂,乙醇和蒸馏水为溶剂,通过混合搅拌、沉淀和去除模板剂等过程来制备得到LaMnO_(3)。利用粉末X射线衍射技术(XRD)、场发射扫描电子显微镜(SEM)、X射线光电子能谱(XPS)、N_(2)吸附-脱附等手段表征分析了催化剂样品LaMnO_(3),并对其进行了电化学性能测试。结果表明,以PMMA微球为模板可制备出球形空洞的多孔LaMnO_(3),其具有良好的氧还原反应(ORR)活性和氧析出反应(OER)活性,23.005 m^(2)/g的比表面积远大于由共沉淀法制备的LaMnO_(3),当作为铝空气电池阴极催化剂材料时,相比于共沉淀法制备的LaMnO_(3)其恒流放电稳定、放电电压高。

PMMA microspheres were prepared by PMMA(polyethyl methacrylate)according to the Stober-Frink method,and used as a template agent.With citric acid as a complexing agent and ethanol and distilled water as solvent,LaMnO_(3) was prepared by mixing and stirring,precipitating and removing the template agent.Powder X-ray diffraction(XRD),field emission scanning electron microscope(SEM),X-ray photoelectron spectroscopy(XPS)and N_(2) adsorption-desorption were used to characterize and analyze the catalyst sample LaMnO_(3),and its electrochemical properties were tested.The results show that the porous LaMnO_(3) with spherical cavity can be prepared using PMMA microspheres as a template,which has good oxygen reduction reaction(ORR)activity,and the specific surface area of 23.005 m^(2)/g is much larger than that of LaMnO_(3) prepared by co-precipitation.When used as cathode catalyst materials for aluminum air batteries,LaMnO_(3) prepared using PMMA microspheres has more stable constant current discharge and higher discharge voltage than that prepared by co precipitation method.