Shojaei Fazel, Mousavi Masoumeh, Nazari Fariba, Illas Francesc
Department of Chemistry, Institute for Advanced Studies in Basic Sciences, Zanjan 45137-66731, Iran.
Phys Chem Chem Phys. 2015 Feb 7;17(5):3659-72. doi: 10.1039/c4cp05109b. Epub 2015 Jan 2.
Density functional theory (DFT)-based calculations were carried out to predict the geometry, energy and electronic structures of the small bimetallic AumPtn (2 ≤m + n≤ 4) clusters deposited on a single-wall (5,5)-carbon nanotube (CNT). The chemical reactivity of these supported bimetallic clusters towards O2 reduction reaction was also considered. The calculations indicate that Au atoms tend to avoid the CNT atoms, whereas the opposite occurs for Pt atoms, a behavior which can be rationalized through analyses of the density of states plots. Compared to isolated clusters, the supported counterparts are found to have significant superiority in catalytic activity towards O2 reduction. The adsorption configuration and identity of the metal (Au or Pt) exposed to the O2 molecule adsorption are the dominant factors in determining the catalytic activity of the supported particles. Most notably, high catalytic activity of the supported clusters is associated with a drastic decrease in adsorption energy of the O2 molecule.
基于密度泛函理论（DFT）进行了计算，以预测沉积在单壁（5,5）-碳纳米管（CNT）上的小双金属AumPtn（2≤m + n≤4）团簇的几何结构、能量和电子结构。还考虑了这些负载型双金属团簇对氧还原反应的化学反应活性。计算表明，Au原子倾向于避开CNT原子，而Pt原子则相反，这种行为可以通过对态密度图的分析来解释。与孤立团簇相比，负载型团簇对氧还原具有显著的催化活性优势。暴露于O2分子吸附的金属（Au或Pt）的吸附构型和特性是决定负载颗粒催化活性的主要因素。最值得注意的是，负载型团簇的高催化活性与O2分子吸附能的急剧降低有关。
