| La1-xCaxMnO3纳米颗粒的制备及氧还原催化性能 |
| Sol-Gel Synthesis of Perovskite La1-xCaxMnO3(x=0~0.4) Nanoparticles for Electrocatalytic Oxygen Reduction |
| 作者 | 单位 | E-mail | | 冯皓 | 先进能源材料化学教育部重点实验室, 南开大学化学学院, 天津 300071 | | | 杜婧 | 先进能源材料化学教育部重点实验室, 南开大学化学学院, 天津 300071 | | | 韩晓鹏 | 先进能源材料化学教育部重点实验室, 南开大学化学学院, 天津 300071 | | | 程方益 | 先进能源材料化学教育部重点实验室, 南开大学化学学院, 天津 300071 | fycheng@nankai.edu.cn | | 陈军 | 先进能源材料化学教育部重点实验室, 南开大学化学学院, 天津 300071 | |
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| 摘要: 本文采用溶胶凝胶法制备了一系列不同Ca含量的钙钛矿型氧化物La1-xCaxMnO3(x=0~0.4)纳米颗粒,X射线粉末衍射及精修、扫描电镜表征显示其相纯度和结晶度高,颗粒平均粒径约40 nm。在0.1 mol·L-1 KOH水溶液中进行的氧还原电催化性能测试显示,La0.7Ca0.3MnO3样品催化活性最高,表观电子转移数接近4,还原电流密度与Pt/C催化剂相当,而催化稳定性优于Pt/C。进一步研究了La1-xCaxMnO3样品中Mn价态、晶胞参数的改变对氧还原催化活性的影响,结果表明当x=0.3时,催化剂中Mn处于混合价态,Mn-O键长适中,最有利于电催化反应。 |
| 关键词: 溶胶凝胶法 钙钛矿 La1-xCaxMnO3 氧还原 电催化 |
| 基金项目: 国家自然科学基金(No.21231005);863课题(2011AA050704);973项目(2011CB935900)和中央高校基本科研业务费专项资金资助项目。 |
| Abstract: In this work, a series of La1-xCaxMnO3 perovskite nanoparticles were prepared through a sol-gel method and investigated as catalysts for the oxygen reduction reaction (ORR). The XRD, SEM and TEM characterization demonstrated high crystallinity of the synthesized particles having diameters of about 40 nm. The crystal structure was determined by Rietveld refinement, indicating variation of the lattice parameters with the amount of substituted Ca. The electrocatalytic properties of the samples were studied using rotating-disk and rotating ring-disk electrode techniques in KOH aqueous solution. Investigations on the composition-performance relationship of La1-xCaxMnO3 perovskites revealed that mixed Mn valence and medium Mn-O bond length favored the ORR electrocatalysis. Among the La1-xCaxMnO3 series, La0.7Ca0.3MnO3 exhibited outstanding ORR activity, enabled an apparent 4-electron pathway and showed superior durability compared to the benchmark carbon-supported Pt nanoparticles. Furthermore, metal-air cells assembled with La0.7Ca0.3MnO3 could deliver high charge and discharge capacity with flat plateaus. The considerable catalytic performances of La1-xCaxMnO3 nanoparticles indicate their promising application as low-cost and high-abundance catalysts in alkaline fuel cells and metal-air batteries. |
| Keywords: sol-gel synthesis perovskite La1-xCaxMnO3 oxygen reduction electrocatalysis |
| 投稿时间：2013-04-03 修订日期：2013-05-10 |
| 摘要点击次数: 2156 |
| 全文下载次数: 2463 |
| 冯皓,杜婧,韩晓鹏,程方益,陈军.La1-xCaxMnO3纳米颗粒的制备及氧还原催化性能[J].无机化学学报,2013,29(8):1617-1625. |
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