Structure of Dealloyed PtCu3 Thin Films and Catalytic Activity for Oxygen Reduction
Structure of Dealloyed PtCu3 Thin Films and Catalytic Activity for Oxygen Reduction
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DOI：
10.1021/cm101090p
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发表时间：
2010-07
影响因子：
8.6
通讯作者：
Ruizhi Yang;J. Leisch;P. Strasser;M. Toney
中科院分区：
文献类型：
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作者：
Ruizhi Yang;J. Leisch;P. Strasser;M. Toney
研究了电化学镀化PtCu3薄膜的详细结构和组成（表面和体积）以及氧还原的催化活性。基于同步辐射的异常x射线衍射（AXRD）表明，在合金膜中形成了一个厚约1.0 nm的富Pt表面区域和一个贫Cu内部区域（与PtCu3的原子比不同），并在Pt表面区域直接观察到压缩晶格应变。通过旋转圆盘电极（RDE）测量，合金PtCu3薄膜比纯Pt薄膜的氧还原活性增加了~ 2.4倍。结果表明，合金Pt−Cu膜的催化活性增强主要是由于表层的压缩应变（配体效应很弱）。我们将薄膜上的结果与纳米颗粒上的相关结果进行了比较。这些研究有助于更好地理解Pt-sk蛋白的结构-组成和结构-活性关系。
The detailed structure and composition (surface and bulk) as well as catalytic activity for oxygen reduction of electrochemically dealloyed PtCu3 thin films have been investigated. Synchrotron-based anomalous X-ray diffraction (AXRD) reveals that a Pt enriched surface region (∼1.0 nm thick) and a Cu depleted interior (atomic ratio different from that of PtCu3) are formed in the dealloyed film, and we directly observe a compressive lattice strain in the Pt surface region. The dealloyed PtCu3 thin films show a ∼2.4 fold increase in the specific oxygen reduction activity over pure Pt thin films as measured by a rotating disk electrode (RDE). Our results show that the enhanced catalytic activity of the dealloyed Pt−Cu film is primarily due to the compressive strain in the surface layer (ligand effect is very weak). We compare our results on thin films to related results on nanoparticles. These studies provide a better understanding of the structure − composition and structure − activity relationships in Pt-sk...