We present here the results of our density-functional-theory-based calculations of the electronic and geometric structures and energetics of Se and O adsorption on Ru 93- and 105-atom nanoparticles. These studies have been inspired by the fact that Se/Ru nanoparticles are considered promising electrocatalysts for the oxygen reduction reaction (ORR) on the direct methanol fuel cell cathodes and the oxygen binding energy is a descriptor for the catalyst activity towards this reaction. We find the character of chemical bonding of Se on a flat nanoparticle facet to be ionic, similar to that obtained earlier for the Se/Ru(0001) surface, while in the case of a low coordinated Ru configuration there is an indication of some covalent contribution to the bonding leading to an increase in Se binding energy. Se and O co-adsorbed on the flat facet, both accept electronic charge from Ru, whereas the adsorption on low-coordinated sites causes more complicated valence charge redistribution. The Se modification of the Ru particles leads to weakening of the oxygen bonding to the particle. However, overall, O binding energies are found to be higher for the particles than for Se/Ru(0001). High reactivity of the Se/Ru nanoparticles found in this work is not favorable for ORR. We thus expect that larger particles with well-developed flat facets are more efficient ORR catalysts than small nanoparticles with a large fraction of under-coordinated adsorption sites.
MOSP: A User-interface Package for Simulating Metal Nanoparticle Structure and Reactivity under Operando Conditions
Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences（中国科学院上海应用物理研究所界面物理与技术重点实验室）；University of Chinese Academy of Sciences（中国科学院大学）；Phonon Science Research Center for Carbon Dioxide, Shanghai Advanced Research Institute, Chinese Academy of Sciences（中国科学院上海高级研究院二氧化碳声子科学研究中心）；Key Laboratory of Low-Carbon Conversion Science & Engineering, Shanghai Advanced Research Institute, Chinese Academy of Sciences（中国科学院上海高级研究院低碳转化科学与工程重点实验室）
Structure and frictional properties of Langmuir-Blodgett films of Cu nanoparticles modified by dialkyldithiophosphate
制备了二烷基二硫代磷酸盐（DDP）修饰铜纳米粒子的LB膜。利用透射电子显微镜（TEM）、X射线光电子能谱学（XPS）和原子/摩擦力显微镜（AFM/FFM）研究了LB膜的结构、微摩擦行为和附着力。结果表明，改性后的纳米铜粒子具有典型的核壳结构和良好的成膜能力。AFM/FFM图像显示改性Cu纳米粒子LB膜由多个纳米粒子紧密有序排列而成，具有良好的低摩擦性能。摩擦环表明纳米铜颗粒的表面坡度对摩擦力有显著影响，摩擦行为表现出明显的“棘轮效应”。粘附实验表明，改性后的纳米铜颗粒具有很小的粘附力。(c)2006 Elsevier B. V.保留所有权利。
Glass transition temperature of PMMA/modified alumina nanocomposite: Molecular dynamic study
在这项研究中，氧化铝和改性氧化铝纳米粒子的PMMA/氧化铝纳米复合材料的影响进行了研究。为了实现这一目标，我们采用分子动力学模拟（MD）方法研究了聚甲基丙烯酸甲酯（PMMA）、PMMA/氧化铝和PMMA/羟基氧化铝纳米复合材料的玻璃化转变行为。所有MD模拟均使用Materials Studio 6.0软件包进行。为了获得玻璃化转变温度，获得密度与温度的变化。将密度-温度曲线的斜率显著变化的温度定义为玻璃化转变温度（Tg）。纳米氧化铝颗粒对聚合物玻璃化转变温度的影响与纳米氧化铝颗粒的自由体积、链段的迁移率以及纳米氧化铝颗粒与聚合物之间的相互作用有关。基于均方位移和回转半径研究了链段的运动性。结果表明，由于氧化铝纳米粒子的改性，PMMA/羟基氧化铝纳米复合材料的玻璃化转变温度的提高幅度大于PMMA/氧化铝纳米复合材料。
Band Structure Modulation of ZrO2 Nanoparticles for Control of CO Adsorption Properties: A Combined Density Functional Theory - Density Functional Tight Binding Study
School of Materials and Chemical Technology, Institute of Science Tokyo（东京科学大学材料化学技术学院）；RIKEN Center for Computational Science（理化学研究所计算科学中心）；Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Gadjah Mada（加查马达大学数学与自然科学学院化学系）
Drying-Induced Atomic Structural Rearrangements in Sodium-Based Calcium-Alumino-Silicate-Hydrate Gel and the Mitigating Effects of ZrO$_2$ Nanoparticles
Oleylamine aging of PtNi nanoparticles giving enhanced functionality for the oxygen reduction reaction
我们报告了一种快速的溶液相策略来合成合金化的PtNi纳米颗粒，其表现出优异的氧还原反应（ORR）功能。这种一锅共还原胶体合成的结果在单分散人口的单晶纳米颗粒的菱形十二面体形态，与Pt富集的边缘和组合物接近Pt 1 Ni 2。我们使用纳米级的3D成分分析，揭示了第一次，油胺（OAM）老化的菱形十二面体Pt 1 Ni 2颗粒的结果在镍浸出从表面刻面，产生老化的颗粒与凹面刻面，一个非常高的表面积和组合物的Pt 2Ni 1。我们表明，改性的原子纳米结构的催化性能超过原来的PtNi菱形十二面体颗粒的2倍以上，也产生改善的循环耐久性。它们的ORR功能远远超过市售的Pt/C纳米颗粒电催化剂，无论是在质量比活性（高达25倍的增加）和固有的面积比活性（高达27倍的增加）。
