Au13: CO Adsorbs, Nanoparticle Responds
Au13: CO Adsorbs, Nanoparticle Responds
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DOI：
10.1021/acs.jpcc.5b03459
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发表时间：
2015-08-13
影响因子：
3.7
通讯作者：
Mpourmpakis, Giannis
中科院分区：
文献类型：
--
作者：
Austin, Natalie;Johnson, J. Karl;Mpourmpakis, Giannis
纳米颗粒的性质与其形态，如形状和大小密切相关。采用密度泛函理论计算和从头算分子动力学模拟相结合的方法，研究了CO在I-h、O-h和平面对称Au纳米颗粒上的吸附行为.我们的研究结果揭示了纳米颗粒的形状特异性吸附响应。相反，在散装的行为，我们观察到一个依赖于d-band中心移动的纳米粒子与CO覆盖，这影响了整体的电子稳定性的nanopartides。结果，我们在高CO覆盖度下观察到2D到3D（平面到I-h）的转变。由于与吸附的CO分子的相互作用，3D纳米颗粒可以在其核心中容纳比2D更多的电荷。所有这些效应导致在I-h Au纳米颗粒上观察到非常规的、更强的CO吸附，其暴露出比平面Au-13的外围原子（外围CN = 3.4）更高的表面配位数（CN = 6）。这项工作突出了小尺寸Au纳米粒子（直径约为1 nm）的吸附行为的形状效应。
Nanoparticle properties are strongly correlated with their morphologies, such as shape and size. By combining density functional theory calculations with ab initio molecular dynamics simulations, we investigated the CO adsorption behavior on Au nanopartides of I-h, O-h, and planar symmetries. Our results revealed a shape-specific adsorption response of the nanopartides. Contrary to the behavior in bulk, we observe a symmetry-dependent d-band center shift on the nanoparticles with CO coverage, which affects the overall electronic stability of the nanopartides. As a result, we observe 2D to 3D (planar to I-h) transition at high CO coverage. Because of the interactions with the adsorbed CO molecules, the 3D nanoparticles can accommodate more charge in their core than the 2D. All of these effects result in observing an unconventional, stronger CO adsorption on I-h Au nanoparticles that expose higher surface coordination number (CN = 6) than the peripheral atoms of the planar Au-13 (peripheral CN = 3.4). This work highlights the shape effect on the adsorption behavior of small-sized Au nanopartides (similar to 1 nm diameter).