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化学学报
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化学学报 ›› 2008, Vol. 66 ›› Issue (13): 1501-1507.    下一篇

研究论文

Au2n-(n＝1, 2)催化CO氧化反应机理的理论研究

唐典勇*,a 张元勤a 胡常伟b   

  1. (a乐山师范学院化学与生命科学学院 乐山 614004)
    (b四川大学化学学院 成都 610064)
  • 投稿日期:2007-12-09 修回日期:2008-01-27 发布日期:2008-07-14
  • 通讯作者: 唐典勇

Theoretical Study on Mechanism of CO Oxidation Catalyzed by Au2n-(n＝1, 2)

TANG, Dian-Yong *,a ZHANG, Yuan-Qin a HU, Chang-Wei b   

  1. (a College of Chemistry and Life Science, Leshan Teacher’s College, Leshan 614004)
    (b College of Chemistry, Sichuan University, Chengdu 610064)
  • Received:2007-12-09 Revised:2008-01-27 Published:2008-07-14
  • Contact: TANG, Dian-Yong

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采用密度泛函理论B3LYP方法研究了金团簇阴离子 和 催化CO氧化反应的详细机理. 计算结果表明, O2分子比CO分子更容易吸附到金团簇上. 第二分子CO能有效降低较强O—O键断裂所需能量. CO氧化反应过程需要两个CO分子协同进行. 和 催化CO氧化反应均通过碳酸根中间体进行, 活化能分别为0.607 和0.658 eV. 和 都能在常温下有效催化CO氧化反应. 这些结果与以前的实验和理论研究一致.

关键词: 金团簇, CO氧化, 反应机理, 密度泛函

The mechanism of CO oxidation catalyzed by anionic gold clusters and was investigated in detail at the B3LYP level of theory. The computational results indicated that the absorption of O2 molecules on gold clusters is easier than that of CO. The CO oxidation can take place only under the influence of cooperative effects due to the presence of more than one CO molecule. The high activation energies, which are a consequence of the partial breaking of a strong O—O bond, can be lowered by introducing the second CO molecule. The CO oxidation catalyzed by and could proceed through carbonate-like intermediates with the activation barriers of 0.607 and 0.658 eV, respectively. Both and can catalyze effectively the CO oxidation at room temperature. These results are in agreement with the previous experimental and theoretical results.

Key words: gold cluster, CO oxidation, mechanism, density functional theory