Enhanced oxygen reduction activity on surface-decorated perovskite thin films for solid oxide fuel cells
Enhanced oxygen reduction activity on surface-decorated perovskite thin films for solid oxide fuel cells
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DOI：
10.1039/c1ee01245b
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发表时间：
2011-09-01
影响因子：
32.5
通讯作者：
Shao-Horn, Yang
中科院分区：
文献类型：
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作者：
Mutoro, Eva;Crumlin, Ethan J.;Shao-Horn, Yang
钙钛矿的表面修饰可以显著影响其氧还原活性，是一种很有前途的SOFC阴极材料改性新途径。在这项研究中，我们证明了（001）La0.8Sr0.2CoO3-delta（LSC）表面上的少量第二相可以显著激活或钝化电极。采用脉冲激光沉积法在（001）取向的氧化钇稳定的氧化锆（YSZ）基底上制备了LSC（001）微电极，并分别用La、Co和Sr的氢氧化物/碳酸盐修饰电极。“Sr”-修饰使LSC表面的纳米颗粒覆盖率从50%到80%提高了一个数量级，而“La”-修饰和“Co”-修饰分别导致k（q）没有变化和降低。虽然增强的物理起源还没有完全理解，从原子力显微镜，X射线衍射和X射线光电子能谱的结果表明，观察到的k（q）增强“Sr”“装饰的表面可以主要归因于表面Sr富集颗粒和LSC表面之间的催化活性界面区域。
Surface-decoration of perovskites can strongly affect the oxygen reduction activity, and therefore is a new and promising approach to improve SOFC cathode materials. In this study, we demonstrate that a small amount of secondary phase on a (001) La0.8Sr0.2CoO3-delta (LSC) surface can either significantly activate or passivate the electrode. LSC (001) microelectrodes prepared by pulsed laser deposition on a (001)-oriented yttria-stabilized zirconia (YSZ) substrate were decorated with La-, Co-, and Sr-(hydr) oxides/carbonates. "Sr''-decoration with nanoparticle coverage in the range from 50% to 80% of the LSC surface enhanced the surface exchange coefficient, k(q), by an order of magnitude while "La''-decoration and "Co''-decoration led to no change and reduction in k(q), respectively. Although the physical origin for the enhancement is not fully understood, results from atomic force microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy suggest that the observed k(q) enhancement for "Sr''-decorated surfaces can be attributed largely to catalytically active interface regions between surface Sr-enriched particles and the LSC surface.