Ethanol Oxidation on Well-Ordered PtSn Surface Alloy on Pt(111) Electrode
Ethanol Oxidation on Well-Ordered PtSn Surface Alloy on Pt(111) Electrode
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DOI：
10.1021/jp406516v
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发表时间：
2013-08
影响因子：
3.7
通讯作者：
Masashi Nakamura;Risa Imai;N. Otsuka;Nagahiro Hoshi;O. Sakata
中科院分区：
文献类型：
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作者：
Masashi Nakamura;Risa Imai;N. Otsuka;Nagahiro Hoshi;O. Sakata
使用原位扫描隧道显微镜 (STM) 和 X 射线衍射测定了 Pt(111) 上 PtSn 表面合金的表面和亚表面结构。在 HClO4 中，覆盖率 θSn ≤ 0.23 时，通过 STM 观察到 PtSn 合金层的不同有序结构。在 θSn = 0.23 时形成了 (√3 × √7)R19.1° 的上层结构，其畴尺寸较小。这种结构提高了乙醇氧化反应的催化活性并具有高耐久性。 X射线结构分析表明，亚表面Sn含量低于3(2)%，PtSn合金层主要形成于Pt(111)电极表面。 Sn原子从Pt层突出0.02 nm，与Pt3Sn(111)的表面结构相似。 (√3 × √7)R19.1° 结构中的 1 个 Pt 原子与周围的 1 个或 2 个 Sn 原子接触，从而导致 EOR 的最高活性。
Surface and subsurface structures of PtSn surface alloy on Pt(111) were determined using in situ scanning tunneling microscopy (STM) and X-ray diffraction. Different ordered structures of the PtSn alloy layer were observed by STM in HClO4 at coverage of θSn ≤ 0.23. Superstructure of (√3 × √7)R19.1° with small domain size was formed at θSn = 0.23. This structure promoted the catalytic activity for the ethanol oxidation reaction with high durability. X-ray structural analysis showed that the ratio of Sn in the subsurface was below 3(2)%, The PtSn alloy layer was mainly formed at the surface of the Pt(111) electrode. The Sn atoms protruded by 0.02 nm from the Pt layer, which was similar to the surface structure of Pt3Sn(111). One Pt atom in the (√3 × √7)R19.1° structure contacts to one or two surrounding Sn atoms, which lead to the highest activity for the EOR.