To fully understand the properties of functional nanocatalysts including nanoclusters and nanoparticles, it is necessary to know the geometric and electronic structures of the nanostructure. The catalytic properties of noble metal nanoclusters can often be improved by the formation of heterostructures on different support, but little is known about their atomic-scale structures and their interaction with the support materials. Here, we report the size- and support-dependent structures for Au nanoclusters by combining aberration-corrected scanning transmission electron microscopy and density functional theory calculations. We demonstrate lattice-induced epitaxial coherence growth for Au nanoclusters on crystalline substrate of (110) MgO, different from the chainlike or random structures on amorphous carbon support. The time sequential atomic scale observations confirm that Au clusters tend to easily migrate on crystalline MgO support. DFT calculations based on the experiment results imply the CO adsorption on MgO supported Au clusters prefer to bind at apex sites, and the adsorption can induce the 3D structural change of the supported nanoclusters, resulting in the formation of linear and bridge CO species. The results should help to clarify the atomistic origin of shape-, number-, and support-dependent catalytic activity in the supported Au clusters catalysts.

中文翻译：

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原子尺度对不同基质上金簇生长和吸附诱导的结构变化的理解

为了充分理解功能性纳米催化剂（包括纳米团簇和纳米颗粒）的特性，有必要了解纳米结构的几何和电子结构。贵金属纳米团簇的催化性能通常可以通过在不同载体上形成异质结构来改善，但对其原子级结构及其与载体材料的相互作用知之甚少。在这里，我们通过结合像差校正的扫描透射电子显微镜和密度泛函理论计算，报告了金纳米簇的尺寸和与支撑有关的结构。我们证明晶格诱导的（110）MgO的晶体基底上的Au纳米团簇的外延相干生长，与无定形碳载体上的链状或无规结构不同。时序原子尺度的观察证实，Au团簇易于在晶体MgO载体上迁移。基于实验结果的DFT计算表明，CO在MgO负载的Au团簇上的吸附倾向于结合在顶点位置，并且吸附可以诱导负载的纳米簇的3D结构变化，从而导致线性和桥连的CO物种的形成。结果应有助于阐明负载型Au团簇催化剂中形状，数量和与载体有关的催化活性的原子起源。吸附可以诱导被支撑的纳米团簇的3D结构变化，从而导致线性和桥连的CO物种的形成。结果应有助于阐明负载型Au团簇催化剂中形状，数量和与载体有关的催化活性的原子起源。吸附可以诱导被支撑的纳米团簇的3D结构变化，从而导致线性和桥连的CO物种的形成。结果应有助于阐明负载型Au团簇催化剂中形状，数量和与载体有关的催化活性的原子起源。