Au_(2n)^-(n=1,2)催化CO氧化反应机理的理论研究  

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

作　　者：唐典勇[1] 张元勤[1] 胡常伟[2] 

机构地区：[1]乐山师范学院化学与生命科学学院,乐山614004 [2]四川大学化学学院,成都610064

出　　处：《化学学报》2008年第13期1501-1507,共7页Acta Chimica Sinica

基　　金：四川省自然科学基金(No.2008JY0119);四川教育厅科研项目(No.07ZA158)资助项目

摘　　要：采用密度泛函理论B3LYP方法研究了金团簇阴离子Au-2和Au-4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.Au-2和Au-4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0.658eV.Au-4和Au-2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.The mechanism of CO oxidation catalyzed by anionic gold clusters Au2^- and Au4^- 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 Au2^- and Au4^- could proceed through carbonate-like intermediates with the activation barriers of 0.607 and 0.658 eV, respectively. Both Au2^- and Au4^- can catalyze effectively the CO oxidation at room temperature. These results are in agreement with the previous experimental and theoretical results.

关 键 词：金团簇 CO氧化 反应机理 密度泛函 

分 类 号：O643.12[理学—物理化学]