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化学学报
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化学学报 ›› 2005, Vol. 63 ›› Issue (1): 86-90. 上一篇    

研究简报

Au/ZrO2催化CO氧化反应中ZrO2纳米粒子的尺寸效应

张鑫，徐柏庆   

  1. (清华大学化学系有机光电子与分子工程教育部重点实验室分子催化与定向转化研究室 北京100084)
  • 投稿日期:2004-03-05 修回日期:2004-09-07 发布日期:2010-12-10
  • 通讯作者: 徐柏庆

Nano-size Effect of Zirconia in Au/ZrO2 Catalyst for CO Oxidation

ZHANG Xin, XU Bo-Qing   

  1. (Innovative Catalysis Program, Key Lab of Organic Optoelectronics & Molecular Engineering, Department of Chemistry, Tsinghua University, Beijing 100084)
  • Received:2004-03-05 Revised:2004-09-07 Published:2010-12-10
  • Contact: XU Bo-Qing

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从同一ZrO(OH)2出发制备了三种不同尺寸的ZrO2纳米颗粒(ZrO2-CP: 40～200 nm, ZrO2-AN: 18～25 nm, ZrO2-AD: 10～15 nm), 采用沉积-沉淀方法制备了相应的Au/ZrO2催化剂. 用XRD, XRF, TEM和低温N2吸附对ZrO2和Au/ZrO2进行了表征. XRD和TEM分析表明Au/ZrO2样品中Au粒子的平均尺寸为4～5 nm, 而ZrO2的晶相和颗粒大小没有因为“负载”Au粒子而发生变化. CO催化氧化反应的结果表明, Au/ZrO2催化活性随着ZrO2纳米粒子尺寸的减小活性明显增加. TEM/HRTEM结果表明, Au/ZrO2催化剂中Au粒子与ZrO2颗粒接触界面随ZrO2颗粒尺寸的减小而明显增加, 这很可能是含有更小尺寸ZrO2纳米粒子的Au/ZrO2催化剂具有更高催化活性的重要原因.

关键词: 纳米Au催化剂, CO氧化反应, 纳米ZrO2, 纳米尺寸效应, 催化剂表征

This work explores the size-effect of zirconia nanoparticles on the catalysis of Au/ZrO2 for CO oxidation. Zirconia particles with different sizes (ZrO2-CP: 40～200 nm; ZrO2-AN: 18～25 nm; ZrO2-AD: 10～15 nm) was prepared from a single source of ZrO(OH)2 and the deposition-precipitation method was employed to prepare the Au/ZrO2 catalysts. The samples were characterized with XRD, TEM, XRF and nitrogen adsorption measurements. While the Au particles in all the Au/ZrO2 catalysts appeared to show similar sizes (4～5 nm), the catalytic activity order of Au/ZrO2-AD＞Au/ZrO2-AN＞Au/ZrO2-CP revealed clearly that smaller zirconia nanoparticles led to Au/ZrO2 catalyst with higher catalytic activity. The activity improvement by reducing zirconia nanoparticle size seems attributable to the increased Au-zirconia junctions in the catalysts.

Key words: Au catalyst, CO oxidation, zirconia nanoparticle, nano-size effect, catalyst characterization