In situ identification of the metallic state of Ag nanoclusters in oxidative dispersion.
In situ identification of the metallic state of Ag nanoclusters in oxidative dispersion.
复制标题
氧化分散中银纳米团簇金属态的原位识别
DOI：
10.1038/s41467-021-21552-2
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发表时间：
2021-03-03
影响因子：
16.6
通讯作者：
Bao X
中科院分区：
文献类型：
--
作者：
Li R;Xu X;Zhu B;Li XY;Ning Y;Mu R;Du P;Li M;Wang H;Liang J;Chen Y;Gao Y;Yang B;Fu Q;Bao X
氧化分散是一种氧化诱导分散机制，广泛应用于烧结金属催化剂的再生和单原子催化剂的制备。然而，气体-金属-载体相互作用在分散过程中的相互作用，特别是气体-金属相互作用还没有得到很好的说明。在这里，我们展示了氮化硅表面上的银纳米结构在还原/氧化条件下和一氧化碳氧化反应过程中的动态分散。利用环境扫描（透射）电子显微镜和近环境压力光电子能谱/光发射电子显微镜，我们解开了一个新的吸附诱导的分散机制，在这样一个典型的氧化分散过程。通过氧在近金属银纳米团簇上的化学吸附实现的强的气体-金属相互作用是分散的内部驱动力。原位观察表明，分散的近金属银纳米团簇在氧气气氛中冷却时被氧化，这可能会误导对氧化诱导分散的理解。我们从考虑温度和气体压力的动态平衡的观点进一步理解了氧化分散机理，这应该适用于许多其他金属，如金，铜，钯等和其他反应条件。
Oxidative dispersion has been widely used in regeneration of sintered metal catalysts and fabrication of single atom catalysts, which is attributed to an oxidation-induced dispersion mechanism. However, the interplay of gas-metal-support interaction in the dispersion processes, especially the gas-metal interaction has not been well illustrated. Here, we show dynamic dispersion of silver nanostructures on silicon nitride surface under reducing/oxidizing conditions and during carbon monoxide oxidation reaction. Utilizing environmental scanning (transmission) electron microscopy and near-ambient pressure photoelectron spectroscopy/photoemission electron microscopy, we unravel a new adsorption-induced dispersion mechanism in such a typical oxidative dispersion process. The strong gas-metal interaction achieved by chemisorption of oxygen on nearly-metallic silver nanoclusters is the internal driving force for dispersion. In situ observations show that the dispersed nearly-metallic silver nanoclusters are oxidized upon cooling in oxygen atmosphere, which could mislead to the understanding of oxidation-induced dispersion. We further understand the oxidative dispersion mechanism from the view of dynamic equilibrium taking temperature and gas pressure into account, which should be applied to many other metals such as gold, copper, palladium, etc. and other reaction conditions.
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影响因子：
56.9
作者：
Campbell, CT;Parker, SC;Starr, DE
通讯作者：
Starr, DE
影响因子：
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作者：
Li, WX;Stampfl, C;Scheffler, M
通讯作者：
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影响因子：
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作者：
Guo, Donghui;Guo, Qinlin;Bao, Xinhe
通讯作者：
Bao, Xinhe
影响因子：
15
作者：
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通讯作者：
Cargnello, Matteo
影响因子：
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作者：
Jones, John;Xiong, Haifeng;Datye, Abhaya K.
通讯作者：
Datye, Abhaya K.