催化学报

催化学报 ›› 2011, Vol. 32 ›› Issue (1): 86-92.DOI: 10.1016/S1872-2067(10)60165-9

• 研究论文 • 上一篇    下一篇

Pt 的氧化状态对甲醇氧化活性的影响

曾建皇, 舒婷, 廖世军, 梁振兴   

  1. 华南理工大学化学与化工学院, 广东广州510641
  • 收稿日期:2010-07-22 修回日期:2010-10-26 出版日期:2011-01-13 发布日期:2014-05-22

Effect of Pt Oxidation State on Methanol Oxidation Activity

ZENG Jianhuang, SHU Ting, LIAO Shijun, LIANG Zhenxing*   

  1. School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510641, Guangdong, China
  • Received:2010-07-22 Revised:2010-10-26 Online:2011-01-13 Published:2014-05-22

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摘要： 采用NaBH4还原法制备了 XC-72 碳黑负载的 Pt 电催化剂, 并在化学还原后用 H2O2 处理部分催化剂以改变 Pt 的氧化状态, 以期改善 Pt 活性中心上水的离解而提高催化活性. X 射线光电子能谱结果表明, 经 H2O2 处理的催化剂含有较多的氧化态 Pt. 通过循环伏安法和记时电流法考察了经处理和未经处理的催化剂在酸性条件下的甲醇氧化的催化活性. 结果表明, 经氧化法产生的含有较多氧化态 Pt 的催化剂并不能提供活性状态的氧以去除阻碍反应的 CO 中间体, 含有较多金属状态 Pt 的催化剂活性反而更高, 抗 CO 性能更佳.

关键词: 铂, 催化活性, 氧化态, 甲醇氧化

Abstract: Pt catalysts supported on Vulcan XC-72 carbon were prepared by the NaBH4 reduction of H2PtCl6 in the presence of a carbon support. One of the catalysts was deliberately treated with H2O2 after chemical reduction to alter the oxidation state of Pt and to promote methanol oxidation through more efficient water dissociation on the Pt sites. X-ray photoelectron spectroscopy confirmed that H2O2 treatment resulted in a more oxidized Pt catalyst. The electrooxidation of methanol over treated and untreated Pt catalysts in acidic solutions at room temperature was investigated by cyclic voltammetry and chronoamperometry. Despite their design, the more oxidized Pt catalysts could not supply active oxygen capable of removing the reaction-inhibiting CO-like reaction intermediates. As a result the catalytic activity was still largely dependent on the Pt oxidation state with the more “metallic” catalyst showing higher methanol oxidation activity and more CO tolerance.

Key words: platinum, catalytic activity, oxidation state, methanol oxidation