Multiscale modeling of supported metal clusters: Exploring the electronic structure of nano-catalysts

由小质量选择过渡金属团簇(如PDN或PtN)软着陆在金属氧化物表面(Mg0、Ti02、Al203等)上制备的单分散模型催化剂。表示特别适合于与簇上催化反应(例如，CO氧化或非CO反应)的理论计算进行比较的体系。在自旋密度泛函理论框架下的数值研究表明，小的负载型钯团簇表现出有限的磁矩。该项目旨在研究团簇自旋对团簇催化反应的动力学和结果的影响。利用Born-Oppenheimer局域自旋密度分子动力学方法，对重要的环境过程，即CO氧化和担载Pd和Pt团簇上的CO-NO反应，探讨了反应势垒的自旋依赖性、反应物吸附位置的能量学和反应路径的概率。类似于团簇结构形变引发催化反应的“结构突变”，团簇自旋翻转可能导致反应势垒的降低。本研究的主要目的在于探索这种“自旋飞跃性”。

Mono-disperse model catalysts produced by soft-landing of small mass-selected transition metal clusters (e.g. PdN or PtN) on metal-oxide surfaces (Mg0, Ti02, Al203 etc.) represent systems which are especially suitable for a comparison with theoretical calculations of catalytic reactions on clusters (e.g. CO oxidation or NO-CO reaction). Numerical studies in the framework of spin density functional theory have shown that small supported Palladium clusters exhibit finite magnetic moments. The proposed project aims to study the influence of cluster spin on the dynamics and outcome of cluster-catalyzed reactions. Employing the Born-Oppenheimer Local-Spin-Density Molecular Dynamics method, the spin-dependence of reaction barriers, the energetics of the adsorption sites of the reactants and probabilities of reaction pathways will be explored for important environmental processes, namely the CO oxidation and the CO-NO reaction on supported Pd and Pt clusters. In analogy to the so-called "structural fluctionality" where cluster structural deformation initiates a catalytic reaction, cluster spin flips might lead to the lowering of reaction barriers. The main goal of this study consists in the exploration of such a "spin-fluctionality".