Atomic scale dynamics of metal nanoclusters

该项目旨在了解金属纳米催化剂在催化过程中的原子结构动力学，以及它们在外部刺激下作为刚性旋转体/平移体的长程动力学。我们将把封装在单壁碳纳米管测试系统中的金属纳米催化剂(铁、铂)与基于我们新的CC/CS校正的SALVE显微镜的原位透射电子显微镜(TEM)相结合。从而利用加速电压为20-80keV的电子束传递给原子的动能来激发纳米团簇的动力学和反应。同时，为了使加热和电子束驱动的过程彼此分离，将利用加热和冷却支架来评估热促进的过程。此外，还将研究电子束激发的金属纳米团簇的运动，并进一步操纵以研究不同金属纳米团簇之间的相互作用，包括合金催化剂和Janus催化剂的形成。伴随着支持观察到的纳米团簇动力学的原子模拟将被用来阐明纳米催化过程中纳米团簇的结构-性质关系，并揭示电子束刺激纳米颗粒运动的机制。考虑到我们丰富的前期工作和成功的初步结果，我们有信心实施这一计划，促进对金属纳米团簇基本行为的理解。

The project is aiming to understand the atomically structural dynamics of metallic nanocatalyts during catalysis as well as their long rang dynamics as rigid rotators/translators under external stimuli. We will combine metallic nanocatalyts (Fe, Pt) encapsulated in SWNT test systems with the in situ transmission electron microscopy (TEM) based on our new CC/CS-corrected SALVE microscope. Thereby the kinetic energy transferred from the e-beam with accelerating voltage of 20–80 keV to the atoms is utilized to stimulate the nanocluster dynamics and reactions. Meanwhile, to decouple the thermal and electron beam driven processes from each other, heating and cooling holders will be utilized to enable assessment of thermally promoted processes. Moreover, the e-beam stimulated motions of the metallic nanoclusters will be investigated and further manipulated to study the interactions between different metallic nanoclusters, including alloy catalysts and Janus catalysts forming. Accompanying atomistic simulations underpinning the observed dynamics of nanoclusters will be used to elucidate their structure-property relationship during nanocatalysis and reveal the mechanism of nanoparticles’ motion stimulated by e-beam. Considering our abundant preliminary work and successful first results, we have confidence to implement this project and advance understanding of fundamental behavior of metallic nanoclusters.