物理化学学报 >> 2010, Vol. 26 >> Issue (07): 1773-1778.doi: 10.3866/PKU.WHXB20100514

电化学 上一篇    下一篇

层层组装法制备核壳SiO2/Pt粒子及其CO电氧化和原位电化学FTIR光谱

李永军, 周宥辰, 孙世刚   

  1. 固体表面物理化学国家重点实验室, 厦门大学化学化工学院化学系, 福建 厦门 361005
    化学生物传感与计量学国家重点实验室, 湖南大学化学化工学院, 长沙 410082
  • 收稿日期:2009-11-18 修回日期:2010-01-30 发布日期:2010-07-02
  • 通讯作者: 李永军, 孙世刚 E-mail:liyongjunef@gmail.com; sgsun@xmu.edu.cn

Preparation of Core-Shell SiO2/Pt Particles via Layer-by-Layer Assembly and Their Electrooxidation and In-situ Electrochemical FTIR Spectra for CO

LI Yong-Jun, ZHOU You-Chen, SUN Shi-Gang   

  1. State Key Laboratory for Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005,Fujian Province, P. R. China
    State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, P. R. China
  • Received:2009-11-18 Revised:2010-01-30 Published:2010-07-02
  • Contact: LI Yong-Jun, SUN Shi-Gang E-mail:liyongjunef@gmail.com; sgsun@xmu.edu.cn

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摘要：

采用层层组装法合成了核壳SiO2/Pt粒子, 用电化学循环伏安法(CV)和原位电化学傅里叶变换红外(FTIR)光谱研究了SiO2/Pt粒子对CO分子的氧化和吸附行为. 透射电子显微研究表明: 包覆SiO2的Pt壳是由团聚的Pt 纳米微粒构成, 其平均厚度大约为26 nm. CO在SiO2/Pt粒子修饰的玻碳(GC)电极上的主氧化峰为0.49 V (vs SCE), 表现出比本体Pt金属好的催化性能. 电化学FTIR光谱研究发现: 线性CO在SiO2/Pt粒子上的IR吸收带的方向发生倒反, 而且在不同的研究电位下, 每个吸收带劈裂为两个间隔约为14 cm-1的吸收带, 这种劈裂现象在饱和吸附CO的Pt金属表面上是很难观察到的. 这些异常的红外吸收现象可能是由SiO2/Pt 粒子的结构效应导致的.

关键词: 铂, 核壳粒子, 一氧化碳, 电氧化, 原位电化学FTIR光谱

Abstract:

Large-scale core-shell SiO2/Pt particles were synthesized via layer-by-layer assembly. The platinum shell was found to be about 26 nmthick and consisted of Pt nanoparticle aggregates. Cyclic voltammetry (CV) was employed to evaluate the electrocatalytic activity of the as-prepared core-shell SiO2/Pt particles for CO detection. Compared with the bulk Pt catalyst, the main oxidation potential was more negative at about 0.49 V (vs SCE). Moreover, COadsorption behavior was also examined using in-situ electrochemical Fourier transform infrared (FTIR) spectrum. Interestingly, the FTIR spectra showed inverted IR bands of linearly bonded CO and each IR band was split into two bands with an interval of ca 14 cm-1, which was difficult to discern at saturation coverage of CO on the Pt metal surface. Those anomalous phenomena can most probably be attributed to the structural effects of core-shell SiO2/Pt particles.

Key words: Platinum, Core-shell nanoparticle, Carbon monoxide, Electrooxidation, In-situ electrtochemical FTIR spectrum