Unconventional Route to Encapsulated Ultrasmall Gold Nanoparticles for High-Temperature Catalysis

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	Unconventional Route to Encapsulated Ultrasmall Gold Nanoparticles for High-Temperature Catalysis
	T. T. Zhang; H. Y. Zhao; S. N. He; K. Liu; H. Y. Liu; Y. D. Yin; C. B. Gao
	2014
发表期刊	Acs Nano
ISSN	1936-0851
卷号	8 期号:7 页码:7297-7304
摘要	Ultrasmall gold nanoparticles (us-AuNPs, <3 nm) have been recently recognized as surprisingly active and extraordinarily effective green catalysts. Their stability against sintering during reactions, however, remains a serious issue for practical applications. Encapsulating such small nanoparticles in a layer of porous silica can dramatically enhance the stability, but it has been extremely difficult to achieve using conventional sol gel coating methods due to the weak metal/oxide affinity. In this work, we address this challenge by developing an effective protocol for the synthesis of us-AuNP@SiO2 single-core/shell nanospheres. More specifically, we take an alternative route by starting with ultrasmall gold hydroxide nanoparticles, which have excellent affinity to silica, then carrying out controllable silica coating in reverse micelles, and finally converting gold hydroxide particles into well-protected us-AuNPs. With a single-core/shell configuration that prevents sintering of nearby us-AuNPs and amino group modification of the Au/SiO2 interface that provides additional coordinating interactions, the resulting us-AuNP@SiO2 nanospheres are highly stable at high temperatures and show high activity in catalytic CO oxidation reactions. A dramatic and continuous increase in the catalytic activity has been observed when the size of the us-AuNPs decreases from 2.3 to 1.5 nm, which reflects the intrinsic size effect of the Au nanoparticles on an inert support. The synthesis scheme described in this work is believed to be extendable to many other ultrasmall metal@oxide nanostructures for much broader catalytic applications.
部门归属	[zhang, tingting ; zhao, hongyu ; he, shengnan ; liu, kai ; gao, chuanbo] xi an jiao tong univ, frontier inst sci & technol, ctr mat chem, xian 710054, shaanxi, peoples r china. [liu, hongyang] chinese acad sci, shenyang natl lab mat sci, inst met res, shenyang 110016, liaoning, peoples r china. [yin, yadong] univ calif riverside, dept chem, riverside, ca 92521 usa. ; gao, cb (reprint author), xi an jiao tong univ, frontier inst sci & technol, ctr mat chem, xian 710054, shaanxi, peoples r china. ; liuhy@imr.ac.cn ; yadong.yin@ucr.edu ; gaochuanbo@mail.xjtu.edu.cn
关键词	Gold Nanoparticle Silica Coating Core/shell Nanostructure Reverse Micelle Gold Hydroxide Co Oxidation Core-shell Nanocatalysts Silica Shell Mesoporous Silica Particles Oxidation Nanodots Nanorods Size Nanocomposites Nanotubes
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语种	英语
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/73500
专题	中国科学院金属研究所
推荐引用方式 GB/T 7714	T. T. Zhang,H. Y. Zhao,S. N. He,et al. Unconventional Route to Encapsulated Ultrasmall Gold Nanoparticles for High-Temperature Catalysis[J]. Acs Nano,2014,8(7):7297-7304.
APA	T. T. Zhang.,H. Y. Zhao.,S. N. He.,K. Liu.,H. Y. Liu.,...&C. B. Gao.(2014).Unconventional Route to Encapsulated Ultrasmall Gold Nanoparticles for High-Temperature Catalysis.Acs Nano,8(7),7297-7304.
MLA	T. T. Zhang,et al."Unconventional Route to Encapsulated Ultrasmall Gold Nanoparticles for High-Temperature Catalysis".Acs Nano 8.7(2014):7297-7304.