Fang Zongtang, Outlaw Michael A, Dixon David A
Department of Chemistry, The University of Alabama , Shelby Hall, Box 870336, Tuscaloosa, Alabama 35487-0336, United States.
J Phys Chem A. 2017 Oct 12;121(40):7726-7744. doi: 10.1021/acs.jpca.7b07226. Epub 2017 Sep 29.
Group 8 (RuO) (n = 1-4) nanoclusters, their anions, and the hydrolysis reactions of the neutral clusters have been studied with the density functional theory (DFT) as well as coupled cluster CCSD(T) theory. The ground state is predicted to be a singlet and a doublet for the neutral RuO clusters and anionic clusters, respectively. The CCSD(T) method is required to predict the correct ground state. The calculated singlet-triplet gaps (<15 kcal/mol) and fluoride affinities (<95 kcal/mol) are smaller than those of the group 4 (MO) and group 6 (MO) metal oxide clusters. The electron affinities range from 2.2 to 3.4 eV, showing that the RuO clusters are quite reducible. Clustering energies and heats of formation are calculated. The water physisorption energies are predicted to be -10 to -20 kcal/mol with the adsorption energy for the singlet being generally more exothermic than that for the triplet. The hydrolysis reactions are exothermic for the monomer and dimer clusters and are slightly endothermic or neutral for the trimer and tetramer. HO is readily dissociated on the monomer and dimer but not on the trimer and tetramer. The physisorption and chemisorption energies are less exothermic, and the barriers for the hydrolysis reactions are larger for RuO nanoclusters than for the corresponding group 4 ZrO nanoclusters.
利用密度泛函理论（DFT）以及耦合簇CCSD（T）理论研究了第8族（RuO）（n = 1 - 4）纳米团簇、它们的阴离子以及中性团簇的水解反应。预测中性RuO团簇和阴离子团簇的基态分别为单重态和双重态。需要CCSD（T）方法来预测正确的基态。计算得到的单重态 - 三重态能隙（<15 kcal/mol）和氟亲和力（<95 kcal/mol）小于第4族（MO）和第6族（MO）金属氧化物团簇的能隙和亲和力。电子亲合能范围为2.2至3.4 eV，表明RuO团簇具有相当的可还原性。计算了团簇化能和生成热。预测水的物理吸附能为 -10至 -20 kcal/mol，单重态的吸附能通常比三重态的更放热。单体和二聚体团簇的水解反应是放热的，而三聚体和四聚体的水解反应略微吸热或呈中性。HO很容易在单体和二聚体上解离，但在三聚体和四聚体上则不然。RuO纳米团簇的物理吸附和化学吸附能放热较少，水解反应的势垒比相应的第4族ZrO纳米团簇更大。
