中国科学院大连化学物理研究所机构知识库
Advanced  
DICP OpenIR  > 中国科学院大连化学物理研究所  > 会议论文
学科主题: 物理化学
题名: A general approach to synthesize thermally stable and highly active Au-Ag alloy nanoparticles supported on inert supports
作者: Liu XY(刘晓燕) ;  Wang AQ(王爱琴) ;  Li L(李林) ;  Zhang T(张涛)
会议名称: GOLD 2009(The 5th international conference on gold science, technology and its applications)
会议日期: 2009-7-26
出版日期: 2009-07-26
会议地点: 德国
其他题名: 一种在惰性载体上制备高热稳定性高活性的Au-Ag合金纳米粒子的通用的方法
通讯作者: Tao Zhang
部门归属: 十五室
主办者: 世界金协会,海德堡大学
摘要: It has been widely accepted that the particle size of the supported gold catalysts plays a key role in determining the catalytic performances. Generally, small-sized gold nanoparticles are obtained on active supports (TiO2, Fe2O3, Co3O4, etc.) by deposition-precipitation (DP) or co-precipitation (CP) method. While on inert supports such as silica, it still remains a challenge to prepare highly dispersed gold nanoparticles. In this work, we developed a general two-step method to prepare small-sized (~ 3 nm), thermally stable, and highly active Au-Ag alloy nanoparticles supported on inert supports such as commercial silica, Al2O3 and SBA-15. In this two-step method, AuCl4- ions were first adsorbed on amine-modified silica surface and reduced by NaBH4 to form small-sized gold particles. Then, Ag+ cations were allowed to adsorb on the negatively-charged gold surface. The recovered solid was calcined at 500 oC in air and reduced at 550 oC in H2 to obtain the supported Au-Ag alloy nanoparticles. Ultraviolet-visible spectroscopy (UV-vis) and high-resolution transmission electron microscopy (HRTEM) were employed to trace the each preparation step for exploring the formation mechanism of the Au-Ag alloy nanoparticles. The results show that silver plays an important role in stabilizing the particles. During the high-temperature calcination in air, a thin layer of silver oxide species forms on the surface of the gold nanoparticles, serving as a passivating agent and preventing the aggregation of the nanoparticles. The high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) image in Figure 1 clearly shows that the Au-Ag alloy nanoparticles supported on the commercial silica are very small and uniform. More intriguing, they are highly stable against the high temperature calcinations. Such-prepared Au-Ag/SiO2 catalyst exhibited very high reactivity in low-temperature CO oxidation, even comparable with that of the Au/TiO2 which is one of the most active gold catalysts. In conclusion, we developed a general strategy to obtain small-sized, thermally stable and highly active Au-Ag nanoparticles on commercially available silica and alumina supports. We believe this method can be extended to a variety of other supports with rich hydroxyl groups on their surfaces. This strategy of stabilizing the gold particles by alloying with a second metal paves a novel way for controlling the particle sizes and for enhancing the thermal stabilities of gold particles, in particular on those inert supports.
语种: 中文
内容类型: 会议论文
URI标识: http://cas-ir.dicp.ac.cn/handle/321008/113526
Appears in Collections:中国科学院大连化学物理研究所_会议论文

Files in This Item:

There are no files associated with this item.


Recommended Citation:
Liu XY,Wang AQ,Li L,et al. A general approach to synthesize thermally stable and highly active Au-Ag alloy nanoparticles supported on inert supports[C]. 见:GOLD 2009(The 5th international conference on gold science, technology and its applications). 德国. 2009-7-26.
Service
 Recommend this item
 Sava as my favorate item
 Show this item's statistics
 Export Endnote File
Google Scholar
 Similar articles in Google Scholar
 [刘晓燕]'s Articles
 [王爱琴]'s Articles
 [李林]'s Articles
CSDL cross search
 Similar articles in CSDL Cross Search
 [刘晓燕]‘s Articles
 [王爱琴]‘s Articles
 [李林]‘s Articles
Related Copyright Policies
Null
Social Bookmarking
  Add to CiteULike  Add to Connotea  Add to Del.icio.us  Add to Digg  Add to Reddit 
所有评论 (0)
暂无评论
 
评注功能仅针对注册用户开放,请您登录
您对该条目有什么异议,请填写以下表单,管理员会尽快联系您。
内 容:
Email:  *
单位:
验证码:   刷新
您在IR的使用过程中有什么好的想法或者建议可以反馈给我们。
标 题:
 *
内 容:
Email:  *
验证码:   刷新

Items in IR are protected by copyright, with all rights reserved, unless otherwise indicated.

 

 

Valid XHTML 1.0!
Powered by CSpace