Atomically Precise Au25(SR)18 Nanoparticles as Catalysts for the Selective Hydrogenation of α,β-Unsaturated Ketones and Aldehydes
Atomically Precise Au25(SR)18 Nanoparticles as Catalysts for the Selective Hydrogenation of α,β-Unsaturated Ketones and Aldehydes
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DOI：
10.1002/anie.200906249
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发表时间：
2010-01-01
影响因子：
16.6
通讯作者：
Jin, Rongchao
中科院分区：
文献类型：
--
作者：
Zhu, Yan;Qian, Huifeng;Jin, Rongchao
金纳米粒子被发现能够催化多种反应，如选择性氧化和氢化;[1-3]近年来人们一直在努力解开金纳米粒子催化性能的起源。[4-7]然而，在大多数研究中，纳米颗粒是多分散的;即使在最好的情况下，颗粒分散度仍然约为5%。因此，所观察到的Au纳米颗粒的催化性能仅反映了系综平均。目前，还没有成功地制备原子级单分散的金纳米颗粒催化剂。Au纳米颗粒的多分散性和它们未知的表面结构排除了颗粒结构和电子性质与它们的催化性能的精确相关性。因此，为了了解其催化性能的起源，它是至关重要的，首先获得原子精确的Au nanoparticle.We最近已经成功地制备原子精确的，硫醇盐稳定的金纳米粒子（称为Aun（SR）m，其中n和m分别代表金原子和配体的数量）。[8-11]这些超小的纳米颗粒构成了一个明确的系统，可以用于催化。基于它们的晶体结构，这些Au颗粒将允许颗粒结构与催化性能的相关性和颗粒上的催化活性位点的识别;后者长期以来一直在纳米催化中进行，但是活性位点难以用常规的多分散纳米颗粒确定，因为颗粒表面结构是未知的。在系列的Aun（SR）m纳米粒子中，我们已经解决了由硫醇盐配体（Au 25（SR）18，其中SR表示硫醇盐）稳定的Au 25纳米粒子的晶体结构，并且还研究了它们的电子结构。[12-14]由于这些颗粒是明确定义的，并且它们的晶体结构是已知的，我们应该能够研究金纳米颗粒催化的一些基本方面。Au 25结构[12]可以被视为Au 13二十面体核心（富电子），由外部12个金原子（缺电子）组成的不完整壳层包裹。[12-14]我们推测富电子的Au 13核可能有助于吸附，
Gold nanoparticles have been found to be capable of catalyzing a variety of reactions, such as selective oxidation and hydrogenation;[1–3] intense efforts have been made in recent years in hope of unravelling the origin of the catalytic properties of gold nanoparticles.[4–7] However, in most studies the nanoparticles are polydispersed; even in the best case the particle dispersity is still about 5%. Therefore, the observed catalytic properties of Au nanoparticles reflect only an ensemble average. Hitherto, there has been no success in preparing atomically monodisperse gold nanoparticle catalysts. The polydispersity of Au nanoparticles and their unknown surface structure preclude the precise correlation of particle structure and electronic properties with their catalytic properties. Thus, in order to understand the origin of their catalytic properties, it is critical to first obtain atomically precise Au nanoparticles.We have recently succeeded in preparing atomically precise, thiolate-stabilized gold nanoparticles (referred to as Aun (SR) m, where n and m represent the number of gold atoms and ligands, respectively).[8–11] These ultrasmall nanoparticles constitute a well-defined system and may be utilized for catalysis. On the basis of their crystal structures, these Au particles will permit a correlation of particle structure with catalytic properties and an identification of catalytically active sites on the particle; the latter has long been pursued in nanocatalysis, but active sites are difficult to determine with conventional polydisperse nanoparticles since the particle surface structure is unknown. Among the series of Aun (SR) m nanoparticles, we have solved the crystal structure of Au25 nanoparticles stabilized by thiolate ligands (Au25 (SR) 18, where SR denotes thiolate) and also have studied their electronic structure.[12–14] As these particles are well defined and their crystal structure is known, we should be able to study some fundamental aspects of gold nanoparticle catalysis. The Au25 structure [12] can be viewed as a Au13 icosahedral core (which is electron-rich) encapsulated by an incomplete shell consisting of the exterior 12 gold atoms (which are electron-deficient).[12–14] We speculate that the electron-rich Au13 core may facilitate the adsorption and