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化学学报
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化学学报 ›› 2006, Vol. 64 ›› Issue (6): 458-462. 上一篇    下一篇

研究论文

铂电极上吸附芳香分子的表面增强红外光谱研究

严彦刚，徐群杰，蔡文斌*   

  1. (1复旦大学化学系 上海市分子催化和功能材料重点实验室 上海 200433)
    (2上海电力学院环境工程系 上海 200090)
  • 投稿日期:2005-08-02 修回日期:2005-12-05 发布日期:2006-03-28
  • 通讯作者: 蔡文斌

Study of Electroadsorption of Aromatic Molecules on Pt Electrodes with Surface Enhanced IR Absorption Spectroscopy

YAN Yan-Gang, XU Qun-Jie, CAI Wen-Bin*   

  1. (1 Shanghai Key Laboratory for Molecular Catalysis and Innovative Materials and Department of Chemistry,
    Fudan University, Shanghai 200433)
    (2 Department of Environmental Engineering, Shanghai University of Electric Power, Shanghai 200090)
  • Received:2005-08-02 Revised:2005-12-05 Published:2006-03-28
  • Contact: CAI Wen-Bin

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1130

被引次数

44 | 4

应用衰减全反射表面增强红外吸收光谱法分别研究了0.1 mol•L－1 HClO4中对硝基苯甲酸(PNBA)和0.1 mol•L－1 KClO4中吡啶(Py)在铂电极上的吸脱附. 结果表明在较高电位下(0.3～0.7 V vs. SCE) PNBA是通过其羧基脱质子后羧酸根的两个氧原子等位吸附在Pt电极表面, 而随着电位的负移, 除PNBA逐步脱附外, 还呈现出单个氧原子吸附的谱学特征. 光谱强度与电位的关系表明PNBA在铂电极表面吸脱附的中间电位约为0.2 V vs. SCE. 吡啶的吸附主要是通过氮原子的孤对电子及脱氢后的α碳原子与Pt电极表面键合. 在较宽的电位区间(0.4～－0.4 V vs. SCE)吡啶的吸附方式和取向基本维持不变.

关键词: 表面增强红外吸收光谱, 铂纳米薄膜电极, 对硝基苯甲酸, 吡啶, 吸附

In situ ATR surface-enhanced IR absorption spectroscopy (ATR-SEIRAS) has been applied to study the adsorption of p-nitrobenzoic acid (PNBA) in 0.1 mol•L－1 HClO4 or pyridine (Py) in 0.1 mol•L－1 KClO4 on Pt electrodes. The results indicate that adsorption of PNBA at positive potential of 0.3 V vs. SCE yielded p-nitrobenzoate species bound to the surface through the carboxylate oxygen atoms with a bridging coordination. The PNBA was desorbed gradually as the potential shifted negatively, and might adopt single oxygen-atom coordination to H-bonded Pt surface. The transition potential for electroadsorption of PNBA on Pt electrodes was centered at ca. 0.2 V vs. SCE. As for the adsorption of Py on Pt electrodes, spectroscopic evidence pointed to the formation of α-pyridyl species nearly perpendicular to the Pt surface. Over the potential range between －0.4 and 0.4 V vs. SCE, the configuration and orientation of adsorbed Py remained virtually unchanged.

Key words: surface-enhanced infrared absorption spectroscopy, platinum nanofilm electrode, para-nitrobenzoic acid, pyridine, adsorption