物理化学学报 >> 2015, Vol. 31 >> Issue (2): 199-203.doi: 10.3866/PKU.WHXB201412011

通讯 上一篇    下一篇

Pt纳米晶上CO电吸附及电氧化的表面增强红外吸收光谱研究

热依莎·多里坤1, 阳耀月2, 蔡文斌1   

  1. 1. 复旦大学化学系, 上海市分子催化与功能材料重点实验室, 上海 200433;
    2. 西南民族大学化学与环境保护工程学院, 成都 610041
  • 收稿日期:2014-09-12 修回日期:2014-11-28 发布日期:2015-01-26
  • 通讯作者: 阳耀月, 蔡文斌 E-mail:yaoyueyoung@163.com;wbcai@fudan.edu.cn
  • 基金资助:

    国家自然科学基金(21273046)资助项目

Surface Enhanced Infrared Absorption Spectroscopic Investigation of CO Electrosorption and Electrooxidation on Pt Nanocrystals

DUOLIKUN Reyisha1, YANG Yao-Yue2, CAI Wen-Bin1   

  1. 1. Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Department of Chemistry, Fudan University, Shanghai 200433, P. R. China;
    2. College of Chemistry and Environment Protection Engineering, Southwest University for Nationalities, Chengdu 610041, P. R. China
  • Received:2014-09-12 Revised:2014-11-28 Published:2015-01-26
  • Contact: YANG Yao-Yue, CAI Wen-Bin E-mail:yaoyueyoung@163.com;wbcai@fudan.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (21273046).

摘要:

为理解Pt 纳米晶(NCs)表面上吸附与反应的结构效应, 本文利用电化学衰减全反射-表面增强红外吸收光谱(ATR-SEIRAS)初步研究了{100}优先取向的Pt 纳米晶表面CO电吸附和电氧化. 合成并清洗过的Pt 纳米晶在硫酸溶液中的循环伏安图出现了四对氧化还原峰, 其中位于0.26和0.36 V的峰分别对应于短程有序和长程有序Pt{100}上的氢吸脱附. 利用Bi、Ge 不可逆吸附法估算出Pt{100}和Pt{111}纳米晶筹分别占34% 和17%. 在原位红外光谱研究中, 首次分辨出线性吸附的CO (COL)物种在Pt 纳米晶的三个基础小晶面上的振动谱峰. 动电位光谱分析结果表明Pt{110}上吸附的COL优先电氧化, 其次{111}上的COL发生氧化, 而Pt{100}上COL氧化过电位最高.

关键词: Pt纳米晶, CO, 电吸附, 电氧化, 表面增强红外吸收光谱

Abstract:

Electrochemical attenuated total reflection-surface enhanced infrared absorption spectroscopy (ATRSEIRAS) has been used to investigate the facet-dependent adsorption and oxidation of CO on the {100}- preferred Pt nanocrystals (NCs). The cyclic voltammogram for the synthesized and then cleaned Pt NCs in a sulfuric acid solution displayed four pairs of redox peaks. The peaks located at 0.26 and 0.36 V were attributed to interfacial hydrogen electro-adsorption/desorption processes on the short- and long-range Pt{100} domains, respectively. Furthermore, the Pt{100} and Pt{111} domains were estimated to account for 34% and 14% of the active sites on the surfaces of the Pt NCs, respectively, based on Bi and Ge irreversible adsorption methods. Potential-dependent spectral features can be used to differentiate the adsorption and oxidation processes of linearly adsorbed CO (COL) species on the three basic planes of the Pt NCs. COL species on the Pt{110} facets were oxidized preferentially, followed sequentially by those on the Pt{111} and Pt{100} facets. COL on Pt{100} required the highest overpotential for their oxidation.

Key words: Pt nanocrystal, CO, Electrosorption, Electrooxidation, Surface enhanced infrared absorption spectroscopy

MSC2000: 

  • O646