Ultrastable single-atom gold catalysts with strong covalent metal-support interaction (CMSI)
Ultrastable single-atom gold catalysts with strong covalent metal-support interaction (CMSI)
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DOI：
10.1007/s12274-015-0796-9
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发表时间：
2015-09-01
期刊：
影响因子：
9.9
通讯作者：
Liu, Jingyue (Jimmy)
中科院分区：
文献类型：
--
作者：
Qiao, Botao;Liang, Jin-Xia;Liu, Jingyue (Jimmy)
负载型贵金属纳米粒子（包括纳米团簇）广泛应用于许多工业催化过程。虽然精细分散的纳米结构是高度活性的，但它们通常是化学不稳定的，并且在升高的温度下倾向于聚集或烧结。这种情况对于负载型纳米金催化剂尤其如此，因为金纳米结构在高温下、在反应条件下或甚至在环境温度下储存期间容易烧结。在这里，我们证明了孤立的Au单原子分散在氧化铁纳米晶（Au-1/FeOx）是更sinteringresistance比Au纳米结构，并表现出极高的反应稳定性CO氧化在一个很宽的温度范围内。理论研究表明，Au 1原子表面带正电荷，并以高价态固定，形成了明显的共价金属-载体相互作用（CMSIs），从而提供了超稳定性和卓越的催化性能。这一工作为制备具有超高稳定性的负载型Au催化剂提供了新的思路和途径。
Supported noble metal nanoparticles (including nanoclusters) are widely used in many industrial catalytic processes. While the finely dispersed nanostructures are highly active, they are usually thermodynamically unstable and tend to aggregate or sinter at elevated temperatures. This scenario is particularly true for supported nanogold catalysts because the gold nanostructures are easily sintered at high temperatures, under reaction conditions, or even during storage at ambient temperature. Here, we demonstrate that isolated Au single atoms dispersed on iron oxide nanocrystallites (Au-1/FeOx) are much more sinteringresistant than Au nanostructures, and exhibit extremely high reaction stability for CO oxidation in a wide temperature range. Theoretical studies revealed that the positively charged and surface-anchored Au1 atoms with high valent states formed significant covalent metal-support interactions (CMSIs), thus providing the ultra-stability and remarkable catalytic performance. This work may provide insights and a new avenue for fabricating supported Au catalysts with ultra-high stability.