物理化学学报 >> 2015, Vol. 31 >> Issue (9): 1753-1760.doi: 10.3866/PKU.WHXB201507091

催化和表面科学 上一篇    下一篇

TiOx/SiO2复合载体上高分散Au催化剂的CO氧化性能

李晓坤,马冬冬,郑燕萍,张宏,丁丁,陈明树*(),万惠霖   

  • 收稿日期:2015-04-16 发布日期:2015-09-06
  • 通讯作者: 陈明树 E-mail:chenms@xmu.edu.cn
  • 基金资助:
    国家重点基础研究发展规划项目(973)(2010CB732303, 2013CB933102);教育部重大研究计划(309019);国家自然科学基金(20923004, 21033006, 21073149, 21273178);教育部创新研究团队项目(IRT1036)

Performance of CO Oxidation over Highly Dispersed Gold Catalyst on TiOx/SiO2 Composite Supports

Xiao-Kun. LI,Dong-Dong. MA,Yan-Ping. ZHENG,Hong. ZHANG,Ding. DING,Ming-Shu. CHEN*(),Hui-Lin. WAN   

  • Received:2015-04-16 Published:2015-09-06
  • Contact: Ming-Shu. CHEN E-mail:chenms@xmu.edu.cn
  • Supported by:
    the National Key Basic Research Program of China (973)(2010CB732303, 2013CB933102);Major Project of ChineseMinistry of Education(309019);National Natural Science Foundation of China(20923004, 21033006, 21073149, 21273178);Program forInnovative Research Team in University, China(IRT1036)

摘要:

负载型Au催化剂中金与载体间存在相互作用,载体性质能够影响Au纳米颗粒分散度及稳定性.本文通过表面溶胶-凝胶(SSG)法制备了TiOx/SiO2复合载体,以期增加氧化物载体表面配位不饱和度从而使其具有较高的金属分散性,并利用低能离子散射(LEIS)谱、X射线光电子能谱(XPS)、X射线衍射(XRD)、透射电子显微镜(TEM)及N2物理吸附(BET)等手段对载体及催化剂进行表征分析.实验表明TiOx/SiO2复合载体表面TiOx分散性良好,没有形成明显的TiO2晶相,且与SiO2间形成Ti―O―Si键.与Au/TiO2相比, Au/TiOx/SiO2催化剂中Au纳米颗粒的分散性更好,因而CO氧化活性显著提高. TiOx/SiO2复合载体上的TiO2膜是Au的主要表面键合位,导致Au与载体间相互作用增强,从而使得Au纳米颗粒抗烧结能力提高,同时催化剂反应稳定性得到改善.

关键词: 金, 纳米颗粒, TiOx/SiO2复合载体, 一氧化碳氧化, 二氧化钛

Abstract:

Supports have a significant effect on the dispersion and stability of Au nanoparticles because of the support-metal interaction. In the present work, TiOx/SiO2 composite supports were prepared by the surface sol-gel (SSG) method to enhance the binding strength between the metal and the support. The samples were characterized by low-energy ion scattering (LEIS) spectroscopy, X-ray photoelectron spectroscopy (XPS), Xray diffraction (XRD), transmission electron microscopy (TEM), and N2 physisorption (BET). The results showed that the TiOx species in TiOx/SiO2 were highly dispersed on SiO2 with the formation of Ti―O―Si linkages. The catalytic activity and stability for CO oxidation on Au/TiOx/SiO2 were significantly enhanced, because of the better dispersion of Au nanoparticles compared with Au/TiO2.

Key words: Gold, Nanoparticle, TiOx/SiO2 composite support, CO oxidation, Titania

MSC2000: 

  • O643