Ag2-

用密度泛函理论B3LYP方法详细研究了 催化CO氧化反应的机理. 计算结果表明, O2分子在 和 上吸附能相差不大, 而CO分子在 上吸附要比在 上弱得多. 催化CO氧化反应共有四条反应途径. 最可能反应通道为CO插入 中的Ag—O键形成中间体[Ag—AgC(O—O)O]－, 然后直接分解形成产物CO2和 , 或另一分子CO进攻中间体[Ag—AgC(O—O)O]－形成两分子产物CO2和 . 在动力学上最难进行的反应通道为经历碳酸根双银中间体, 需要克服约0.24 eV的能垒. 催化CO氧化反应活性要高于 .

Theoretical Study on Mechanism of CO Oxidation Catalyzed by Ag2-

The mechanism of -catalyzed CO oxidation was investigated at the level of B3LYP theory. The computational results indicate that the absorption energy of O2 on is close to that of O2 on , while the absorption of CO on is stronger than that of CO on . There are four reaction pathways for CO oxidation catalyzed by . The most feasible pathway is the CO insertion into the Ag—O bond of to produce an intermediate [Ag—AgC(O—O)O]－, and then the intermediate [Ag—AgC(O—O)O]－ decomposes into product CO2 and , or another CO molecule attacks [Ag—AgC(O—O)O]－ to form two CO2 molecules and anion. The most difficult pathway is the di-silver carbonate intermediate pathway, which needs to overcome a total energy barrier of about 0.24 eV. Since for gold, the carbonate-like intermediate pathway requires an activation barrier of 0.61 eV, silver proves to be a better catalyst than gold.