Department of Chemistry, National Taiwan Normal University, No. 88, Section 4, Tingchow Road, Taipei 116, Taiwan.
Phys Chem Chem Phys. 2014 Mar 21;16(11):5393-8. doi: 10.1039/c3cp54667e.
We applied density-functional theory (DFT) to investigate the adsorption and dissociation of NO on Rh19 and Ni19 clusters with a double-icosahedral (DI) structure. The transition structures of the NO dissociating on the potential-energy surfaces were derived using the nudged-elastic-band (NEB) method. The adsorption energies of NO molecules on the rhombus-center region of DI clusters are -2.53 eV and -2.78 eV with the N-O bond elongated to 1.33 Å and 1.35 Å, respectively, on Ni19 and Rh19, compared to 1.16 Å of the gaseous NO counterpart. The barriers to dissociation of N-O on both DI-Rh19 (Ea = 0.24 eV) and DI-Ni19 (Ea = 0.42 eV) clusters are small, indicating that the rhombus-center region of DI metal clusters might activate the scission of the N-O bond. To understand the interaction between these nanocluster catalysts and their adsorbates, we calculated the electronic properties including the local densities of states, orbital evolution of the adsorbates and interaction energies; the results indicate that a profound catalytic behavior for bond scission is observed in this unique rhombus-center region of DI metal-nanoclusters.
我们应用密度泛函理论（DFT）研究了具有双二十面体（DI）结构的 Rh19 和 Ni19 团簇对 NO 的吸附和离解。使用键轨迹弹性带（NEB）方法得出了在势能表面上 NO 离解的过渡态结构。NO 分子在 DI 团簇的菱形中心区域的吸附能分别为 -2.53 eV 和 -2.78 eV，N-O 键分别拉长至 1.33 Å 和 1.35 Å，而气态 NO 的键长为 1.16 Å。与 DI-Ni19（Ea = 0.42 eV）团簇相比，DI-Rh19（Ea = 0.24 eV）团簇中 N-O 键的离解势垒较小，表明 DI 金属团簇的菱形中心区域可能会激活 N-O 键的断裂。为了了解这些纳米团簇催化剂与其吸附物之间的相互作用，我们计算了包括局域态密度、吸附物轨道演化和相互作用能在内的电子性质；结果表明，在 DI 金属纳米团簇的这种独特的菱形中心区域观察到了对键断裂的深刻催化行为。
