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Total structure determination of surface doping [Ag46Au24(SR)32](BPh4)2 nanocluster and its structure-related catalytic property.

Wang S, Jin S, Yang S, Chen S, Song Y, Zhang J, Zhu M - Sci Adv (2015)

Bottom Line: The structure effect is widely present in the catalysis of alloy systems.This is the first case to find the structure effect in atomically precise alloy nanoclusters.Our work will benefit the basic understanding of bimetal distribution, as well as the structure-related catalytic property of alloy nanoclusters at the atomic level.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry and Center for Atomic Engineering of Advanced Materials, Anhui University, Hefei, Anhui 230601, People's Republic of China.

ABSTRACT
The structure effect is widely present in the catalysis of alloy systems. However, the surface structure of this system is still ambiguous because of the limitations of the current surface characterization tools. We reported the x-ray crystallographic structure of the first and the largest AgAu alloy nanocluster with a doping shell formulated as [Ag46Au24(SR)32](BPh4)2. This nanocluster consists of an achiral bimetallic Ag2@Au18@Ag20 core protected by a chiral Ag24Au6(SR)32 shell. The catalysis experiments further revealed that the surface structure affects the selectivity of products significantly. This is the first case to find the structure effect in atomically precise alloy nanoclusters. Our work will benefit the basic understanding of bimetal distribution, as well as the structure-related catalytic property of alloy nanoclusters at the atomic level.

No MeSH data available.


Two different kinds of nanocluster catalysts in the styrene oxidization.The surface-doped nanocluster (NC) shows high selectivity for benzaldehyde, whereas the core-shell structured nanocluster shows high selectivity for epoxide.
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S1: Two different kinds of nanocluster catalysts in the styrene oxidization.The surface-doped nanocluster (NC) shows high selectivity for benzaldehyde, whereas the core-shell structured nanocluster shows high selectivity for epoxide.

Mentions: Table 1 summarizes the results. Epoxide and benzaldehyde were the major products in the styrene oxidation. All catalysts showed high activity compared to plain CNT. Homogold Au25/CNT showed the highest conversion of styrene, that is, 72.8%, whereas the selectivity for benzaldehyde is 66.4%. The homosilver Ag44/CNT showed a much lower conversion (that is, 43.6%) than the homogold nanocluster did but it exhibited a better selectivity for benzaldehyde (that is, 92.6%). Compared with the homometal nanoclusters, surface doping bimetallic Au24Ag46/CNT (Table 1, entry 3) catalysts could increase the selectivity for epoxide (that is, >95%) and give much better conversion (that is, ~70%) than the homosilver nanocluster does. Therefore, the advantages of both the silver (high selectivity for benzaldehyde) and the gold (high conversion) have been well reflected on the surface doping Ag46Au24/CNT catalyst. In contrast, the core-shell structured bimetallic Ag32Au12 nanocluster shows a much lower benzaldehyde selectivity (that is, 37.6%) than does the surface doping catalyst. This finding is remarkable in pioneering investigations on the structure effect in atomically precise alloy nanoclusters and demonstrates a clear synergistic effect of the AgAu alloy catalysts (Scheme 1).


Total structure determination of surface doping [Ag46Au24(SR)32](BPh4)2 nanocluster and its structure-related catalytic property.

Wang S, Jin S, Yang S, Chen S, Song Y, Zhang J, Zhu M - Sci Adv (2015)

Two different kinds of nanocluster catalysts in the styrene oxidization.The surface-doped nanocluster (NC) shows high selectivity for benzaldehyde, whereas the core-shell structured nanocluster shows high selectivity for epoxide.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4643804&req=5

S1: Two different kinds of nanocluster catalysts in the styrene oxidization.The surface-doped nanocluster (NC) shows high selectivity for benzaldehyde, whereas the core-shell structured nanocluster shows high selectivity for epoxide.
Mentions: Table 1 summarizes the results. Epoxide and benzaldehyde were the major products in the styrene oxidation. All catalysts showed high activity compared to plain CNT. Homogold Au25/CNT showed the highest conversion of styrene, that is, 72.8%, whereas the selectivity for benzaldehyde is 66.4%. The homosilver Ag44/CNT showed a much lower conversion (that is, 43.6%) than the homogold nanocluster did but it exhibited a better selectivity for benzaldehyde (that is, 92.6%). Compared with the homometal nanoclusters, surface doping bimetallic Au24Ag46/CNT (Table 1, entry 3) catalysts could increase the selectivity for epoxide (that is, >95%) and give much better conversion (that is, ~70%) than the homosilver nanocluster does. Therefore, the advantages of both the silver (high selectivity for benzaldehyde) and the gold (high conversion) have been well reflected on the surface doping Ag46Au24/CNT catalyst. In contrast, the core-shell structured bimetallic Ag32Au12 nanocluster shows a much lower benzaldehyde selectivity (that is, 37.6%) than does the surface doping catalyst. This finding is remarkable in pioneering investigations on the structure effect in atomically precise alloy nanoclusters and demonstrates a clear synergistic effect of the AgAu alloy catalysts (Scheme 1).

Bottom Line: The structure effect is widely present in the catalysis of alloy systems.This is the first case to find the structure effect in atomically precise alloy nanoclusters.Our work will benefit the basic understanding of bimetal distribution, as well as the structure-related catalytic property of alloy nanoclusters at the atomic level.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry and Center for Atomic Engineering of Advanced Materials, Anhui University, Hefei, Anhui 230601, People's Republic of China.

ABSTRACT
The structure effect is widely present in the catalysis of alloy systems. However, the surface structure of this system is still ambiguous because of the limitations of the current surface characterization tools. We reported the x-ray crystallographic structure of the first and the largest AgAu alloy nanocluster with a doping shell formulated as [Ag46Au24(SR)32](BPh4)2. This nanocluster consists of an achiral bimetallic Ag2@Au18@Ag20 core protected by a chiral Ag24Au6(SR)32 shell. The catalysis experiments further revealed that the surface structure affects the selectivity of products significantly. This is the first case to find the structure effect in atomically precise alloy nanoclusters. Our work will benefit the basic understanding of bimetal distribution, as well as the structure-related catalytic property of alloy nanoclusters at the atomic level.

No MeSH data available.